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Accepted papers to appear in an upcoming issue

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Multi-tenant provisioning over software defined networking enabled metropolitan area quantum key distribution networks

Yuan Cao, Yongli Zhao, Xiaosong Yu, and Jie Zhang

Doc ID: 346933 Received 27 Sep 2018; Accepted 12 Dec 2018; Posted 12 Dec 2018  View: PDF

Abstract: Quantum key distribution (QKD) is potential to provide long-term security for communications across the Internet. As security-hungry applications dramatically rise nowadays, a growing number of QKD networks are promising to be deployed in the immediate future. Nevertheless, a high-security-demand institution (e.g., a bank) needs to pay a high price to deploy its dedicated QKD network, while a cost-effective way of overcoming this challenge is to make multiple tenants share a QKD network. Each tenant represents a high-security-demand institution and can obtain secret keys on demand from the QKD network infrastructure for security purposes. Hence, how to achieve efficient and flexible multi-tenant provisioning over a QKD network becomes a crucial problem. This work introduces software defined networking (SDN) to address this problem. We experimentally demonstrate multi-tenant provisioning (including tenant establishment, adjustment, and deletion) over SDN-enabled metropolitan area QKD networks. A SDN-enabled metropolitan area QKD network architecture is introduced. We present a workflow, protocol extensions, and an on-demand secret-key resource allocation strategy for multi-tenant provisioning, which are all demonstrated by establishing an experimental testbed in the lab. Experimental results verify the effectiveness and flexibility of our SDN-based approaches for multi-tenant provisioning over metropolitan area QKD networks. Moreover, we conduct the simulation and discover the ways of improving the successful probability of multi-tenant provisioning over metropolitan area QKD networks.

Directional Supercontinuum Generation in Waveguides and Fibers

Simon Christensen, Shreesha Rao D S, Ole Bang, and Morten Bache

Doc ID: 345658 Received 17 Sep 2018; Accepted 12 Dec 2018; Posted 13 Dec 2018  View: PDF

Abstract: In this paper we numerically study supercontinuum generation by pumping a silicon nitride waveguide, with two zero-dispersion wavelengths, with femtosecond pulses. The waveguide dispersion is designed so that the pump pulse is in the normal dispersion regime. We show that because of self phase modulation, the initial pulse broadens into the anomalous dispersion regime, which is sandwiched between the two normal-dispersion regimes, and here a soliton is formed. The interaction of the soliton and the broadened pulse in the normal dispersion regime causes additional spectral broadening through formation of dispersive waves by non-degenerate four-wave mixing and cross phase modulation. This broadening occurs mainly towards the second normal dispersion regime. We show that pumping in either normal dispersion regime allows broadening towards the other normal dispersion regime. This ability to steer the continuum extension towards the direction of the other normal dispersion regime, beyond the sandwiched anomalous dispersion regime underlies the directional supercontinuum notation. We numerically confirm the approach in a standard silica microstructured fiber geometry with two zero dispersion wavelengths.

Nonlinear gas sensing based on third harmonic generation in cascaded chalcogenide microfibers

Pan Huang, Tianye Huang, Shuwen Zeng, jianxing pan, Xu Wu, Xiang Zhao, Yiheng Wu, Ping Shum, and Gilberto Brambilla

Doc ID: 347835 Received 09 Oct 2018; Accepted 12 Dec 2018; Posted 13 Dec 2018  View: PDF

Abstract: The performance of conventional gas sensors based on light absorption in the mid-infrared (MIR) faced the challenges of the high-cost and low efficiency of photodetection at these wavelengths. In this paper, a nonlinear gas sensor based on third harmonic generation (THG) in cascaded chalcogenide microfibers is proposed. In the first microfiber section, the input MIR light with “fingerprint” frequency has shown the ability for large amount of gas absorption. The second microfiber section is used for THG pumped by the residual MIR light. In this process, the sensing signal is converted to the near-infrared (NIR) region and the power variation caused by the absorption is amplified due to the nonlinear relation between pump and harmonic signals. According to our analysis, a lowest methane concentration of 7.4×10-8 can be detected at a practically drawable Ae2Se3 microfiber length of 1 cm. Compared to direct MIR gas sensing, the cascaded microfiber sensing has the advantages of improved sensing performance and also shorter the absorption length.

Experimental verification of Faraday rotation enhancement by all-ferrodielectric metasurface

Vladimir Yachin, SERGEY POLEVOY, Liubov Ivzhenko, Sergey Tarapov, and Mark Nakhimovych

Doc ID: 340944 Received 01 Aug 2018; Accepted 11 Dec 2018; Posted 12 Dec 2018  View: PDF

Abstract: An all-ferrodielectric metasurface, formed by two-layer structure consisting of a layer of double periodic array of square prisms of ferrodielectric situated on a dielectric layer has been fabricated and studied in order to demonstrate how the grating mode resonance affects the enhancement of Faraday rotation. The ferrodielectric array allows excitation of the natural modes namely “grating modes” of such array as open microresonators. These modes give rise to the additional resonances in the electromagnetic spectra of the structure and to the enhancement of the Faraday effect. The Faraday effect increases several times with respect to the case of the bare uniform ferrodielectric layer with the same thickness as for the ferrodielectric array.

Numerical experiments on the Fabry-Perot transmission resonances in spatially dispersive metal-dielectric multilayers

Denis Iakushev and Servando Lopez-Aguayo

Doc ID: 342518 Received 17 Aug 2018; Accepted 11 Dec 2018; Posted 12 Dec 2018  View: PDF

Abstract: We study the transmission of electromagnetic waves through regular metal-dielectric arrays, where the metal layers are spatially dispersive while the dielectric layers are media with Kerr-type nonlinearity. We develop an algorithm for determining the electromagnetic field intensity and we show that the transmission spectra of multilayers can change significantly in the presence of even a relatively weak nonlinearity, resulting in multiple possible states of transmitted electromagnetic field. Similary, we report that spatial dispersion of metal layers leads to suppression of nonlinear effects of dielectric ones, reducing the possible number of different states of transmitted electromagnetic field.

Directional quantum state amplification between optical and microwave photons

Wen-An Li, Guang-Yao Huang, and Yuan Chen

Doc ID: 345350 Received 07 Sep 2018; Accepted 11 Dec 2018; Posted 12 Dec 2018  View: PDF

Abstract: Unidirectional amplification of the quantum state between optical and microwave fields is of great importance in signal processing and communication. We propose a hybrid optomechanical system to achieve directional amplification of the quantum state, where three cavities are coupled to a common mechanical resonator. Two cavities function as input cavity and output cavity respectively, while the third cavity is introduced to facilitate the unidirectional transfer between input and output cavities. In our scheme, only three tones are required to realize the directional amplifier. We find that in the large cooperativity limit the amplifier can reach large photon number gain with quantum-limited added noise, with no limitation on the gain-bandwidth product. Furthermore, the directional amplification behavior is controllable by modulating the phase differences between the effective optomechanical couplings.

Dual-band 2-bit coding metasurface for multifunctional control of both spatial waves and surface waves

Shahid Iqbal, Shuo Liu, GUODONG BAI, Muhammad Furqan, Hamza Madni, and Tie Jun Cui

Doc ID: 345529 Received 10 Sep 2018; Accepted 11 Dec 2018; Posted 12 Dec 2018  View: PDF

Abstract: We present a reflection-type 2-bit digital coding metasurface to achieve dual-band functionalities in two different operating bands, independently. We aim to design various coding sequences to achieve the pre-desired functionalities, which no longer require time-consuming optimization of the distribution of reflection phases. Two main contributions are provided in this work. Firstly, we show that by changing the operational frequency band between the lower (X-band) and higher (Ku-band) frequency bands, we can realize the beam switching between the opposite half planes. Secondly, the proposed dual-band 2-bit coding metasurface is further extended for conversion from the spatial waves to surface waves in one frequency band, and beam deflection/focusing in another band. Samples are fabricated to experimentally validate their frequency-dependent performance, which show high efficiency and good agreement with simulations results. We remark that the proposed concept can be readily extended to terahertz and optical regimes, which may find potential applications in multifunctional meta-devices with multispectral features.

Blind modulation format identification using DBSCAN algorithm for continuous variable quantum key distribution

hang zhang, peng liu, ying guo, Ling Zhang, and Duan Huang

Doc ID: 346511 Received 01 Oct 2018; Accepted 10 Dec 2018; Posted 12 Dec 2018  View: PDF

Abstract: Advances in adaptive modulation techniques have fueled the growth of classic communication recently and the modulation format identification (MFI) has been extensively studied in the field of wireless communication, but the MFI concept is worth reviewing for free-space continuous variable quantum key distribution (CV-QKD) system because of a variety of turbulence effects, the detector noise, the quantization noise and other added noise. This paper proposes the constellation MFI based on density-based spatial clustering of applications with noise (DBSCAN) machine learning algorithm, which is mainly used in the receiver of CV-QKD system. The proposed MFI scheme for QPSK, 8-QAM, 16-QAM, 32-QAM and 64-QAM signals can delivering high accuracy (99%) when signal-to-noise ratio (SNR) is greater than or equal to 15 dB. The simulation results show that using the proposed DBSCAN unsupervised machine learning algorithm can achieve good identification performance. Our resluts also show that the proposed MFI scheme can be further improved at lower SNR by optimizing the algorithm and increasing the number of samples.

On anomalously large nano-scale heat transfer between metals

C Henkel and Paul Philip Schmidt

Doc ID: 349850 Received 01 Nov 2018; Accepted 10 Dec 2018; Posted 12 Dec 2018  View: PDF

Abstract: The non-contact heat transfer between two bodies is moreefficient than the Stefan--Boltzmann law, when thedistances are on the nanometer scale (shorter than Wien's wavelength), due to contributions of thermally excited near fields.This is usually described in terms of the fluctuation electrodynamicsdue to Rytov, Levin, and co-workers.Recent experiments in the tip--plane geometry have reported ``giant' heat currents between metallic (gold) objects,exceeding even the expectations of Rytov theory. We discuss a simple modelthat describes the distance dependence of the data and permits to compare to a plate--plate geometry, as in the proximity(or Derjaguin) approximation.We extract an area density of active channels which is of thesame order for the experiments performed by the groups ofKittel (Oldenburg) and Reddy (Ann Arbor). It is argued that mechanisms that couple phonons to an oscillatingsurface polarisation are likely to play a role.

Nanoplasmonic-whispering gallery mode hybrid microresonator for enhancing single molecule Raman scattering and fluorescence

AKASH ARYA, Gour Das, Venkata Dantham, and Ranjit Laha

Doc ID: 348965 Received 22 Oct 2018; Accepted 10 Dec 2018; Posted 10 Dec 2018  View: PDF

Abstract: We propose a high quality factor nanoplasmonic-whispering gallery mode (WGM) hybrid microresonator (HMR) for the enhancement of single molecule Raman scattering signal. Using the reactive sensing principle, we analytically developed a working formula for estimating the enhancement factor (η) that depends on quality factor of WGM as well as on power and wavelength of incident light. Theoretical simulations, carried out using developed theory, revealed that the enhancement due to HMR is at least 1-3 orders higher relative to the conventional surface enhanced Raman scattering technique. The HMR efficiency for obtaining better enhancements was found to depend on efficient evanescent coupling of laser light into the HMR. An experimental setup has also been proposed for the realization of the design and working of HMR for single molecule Raman scattering enhancement. The proposed HMR is also found suitable in enhancing single molecule fluorescence. Finally, suitable nanoplasmonic structures are proposed for making efficient HMRs for studying single molecule Raman scattering/fluorescence and their local field strengths are estimated using finite element method.

Effective nonlinear rovibrational response of water vapor for efficient pulse propagation simulations

Phil Rosenow, Miroslav Kolesik, Stephan Koch, and Jerome Moloney

Doc ID: 348751 Received 19 Oct 2018; Accepted 09 Dec 2018; Posted 10 Dec 2018  View: PDF

Abstract: The long range delivery of high energy long wavlength pulses over kilometer ranges in the atmosphere could be potentially offset by nonlinear spectrally broadband responses of hundreds of thousands of nearby rovibrational transitions of water, CO₂ and other atmospheric constituents. To study this scenario, an effective multi-level optical Bloch equation based approach is developed, extending the linear response of the HITRAN database to capture the nonlinear rovibrational response of water vapor. The model is sufficiently compact and computationally efficient to source the unidirectional pulse propagation equation and enable the first study of long range, 10 μm pulse delivery over hundreds of meters to kilometer distances. The simulation results clearly show that long range delivery is possible due to the low peak intensities achieved in self-trapped multi-Joule pulses.

Simulation of dual-wavelength pumped 3.5 µm CW laser operation of Er:CaF2 and Er:KY3F10 in waveguide configuration

Saiyu luo, Richard Moncorge, Jean-Louis DOUALAN, Huiying XU, Zhiping Cai, Christophe Labbe, Bin Xu, Alain BRAUD, and Patrice Camy

Doc ID: 334731 Received 02 Jul 2018; Accepted 07 Dec 2018; Posted 10 Dec 2018  View: PDF

Abstract: Based on a detailed spectroscopic investigation, a simulation is developed to demonstrate the possibility of multi-watt CW laser operation of highly-doped Er:CaF2 and Er:KY3F10 cubic crystals in waveguide configuration using single- and dual-wavelength pumping. A comparison is made with the results obtained in the case of an Er:ZBLAN fluorozirconate glass in the same conditions.

Quantum plasmonics of metal nanoparticles

Vladimir Bordo

Doc ID: 349944 Received 01 Nov 2018; Accepted 07 Dec 2018; Posted 10 Dec 2018  View: PDF

Abstract: A new theoretical approach which describes quantum optical properties of metal nanoparticles interacting with an electromagnetic field is developed. In the linear regime of interaction, the model treats a metal nanoparticle as a two-level quantum system comprising of the lowest plasmonic Fock states which is governed by the optical Bloch equations. This approach not only agrees with the classical results, but provides also a direct link to quantum optics and cavity quantum electrodynamics that allows one to predict quantum phenomena which are not anticipated from a classical description. The new model is applied to the calculations of the radiative relaxation rate in a nanoparticle, the quantum beats in the intensity of radiation from a nanoparticle dimer and the radiative relaxation rate in both 1D and 2D nanoparticle arrays in close vicinity of a reflective surface.

Quantum Low Probability of Intercept

Jeffrey Shapiro, Don Boroson, Ben Dixon, Matthew Grein, and Scott Hamilton

Doc ID: 347094 Received 01 Oct 2018; Accepted 07 Dec 2018; Posted 13 Dec 2018  View: PDF

Abstract: Conventional cryptography — such as the RSA public-key infrastructure — may be rendered insecure by the ever-increasing capabilities of classical computers and the emergence of quantum computers. Quantum key distribution and post-quantum cryptography are presently being pursued as solutions to the quantum threat, but they offer no protection against an adversary who has obtained decryption keys by hacking the computer where they are stored, or by bribing a code clerk who has access to them. This paper introduces a protocol, which we call quantum low probability of intercept (QLPI), that solves the key-disclosure problem. It transmits a ciphertext in such a way that laws of physics preclude an eavesdropper from obtaining anything but an error-ridden version of that ciphertext. Consequently, even were an adversary to possess the decryption key, the plaintext could not be recovered. Furthermore, QLPI is capable of Gbps communication rates on optical fiber over metropolitan-area distances without space-division or wavelength-division multiplexing and without the need for any new technology.

Ambiguous discrimination among linearly dependent quantum states and its application to two-way deterministic quantum key distribution

hua Lu

Doc ID: 347107 Received 01 Oct 2018; Accepted 06 Dec 2018; Posted 10 Dec 2018  View: PDF

Abstract: It is impossible to distinguish a set of linearly dependent quantum states,which ensures the security of quantum key distribution (QKD).When considering some features such as symmetry, one may distinguish a part ofquantum states from another part, as ambiguous discrimination.In this paper, we demonstrate that two-way deterministic QKD (TDQKD) is immune tophoton-number-splitting (PNS) attacks for two-photon singles.When there are three or more photons in signals, the eavesdropper cangain the key bits deterministically with ambiguous discrimination,without introducing any error rate.Our study presents a conclusion on the security of TDQKD against PNS attacks.

Propagation of circularly and elliptically polarized few-cycle solitons in Kerr medium

ZhanJie Gao, Huijun Li, and Ji Lin

Doc ID: 338312 Received 10 Jul 2018; Accepted 06 Dec 2018; Posted 06 Dec 2018  View: PDF

Abstract: The stability and interaction of circularly and elliptically polarized few-cycle solitons in a Kerr medium are investigated. By means of the multi-scale method, we present a new class of approximate analytical circularly and elliptically polarized few-cycle soliton solutions. Based on the analytical results, it is shown numerically that the circularly and elliptically polarized few-cycle solitons can propagate stably when parameters are properly adjusted. It is proved that the stability of the circularly polarized few-cycle solitons depends on wether their spectrums are in the anomalous-dispersion regime. And for elliptically polarized few-cycle solitons, their stability relies on two factors. Firstly, the elliptically polarized few-cycle solitons are more stable when more part of their spectrums locate in the anomalous dispersion regime. Secondly, the carrier frequency also has influence on the stability of elliptically polarized few-cycle solitons. Further more, the interactions of the two and threecircularly and elliptically polarized few-cycle pulses are studied. When pulse parameters are suitably chosen,we show the elastic collision, inelastic collision and repulsive interactionbetween these multi few-cycle pulses.

Strong tunable photomixing in semi Dirac materials in terahertz regime

Chao Zhang, Sunchao Huang, My Hanh Tran, Jack Zuber, Qian Wang, and Yiming Zhu

Doc ID: 348777 Received 19 Oct 2018; Accepted 04 Dec 2018; Posted 05 Dec 2018  View: PDF

Abstract: We demonstrate a strong and anisotropic photomixing effect in an electronic system whose energy-momentum dispersion behaving parabolic in x direction and linear in y direction, such as a TiO2/VO2 multilayered structure. The third order photo response along the linear and parabolic directions have been analysied and quantitative determined. We found a remarkable tunability of the mixing efficiency along the parabolic direction by a small electric field in the linear direction, up to two orders of magnitude. The the terahertz regime the third order response is comparable to the linear response under an applied field of $10^3-10^4V/cm$. Additionally, the non-linear response persists at room temperature. The results may have applications where different current response is required along different directions in THz regime.

Macroscopic tripartite entanglement of nitrogen–vacancy centers in diamond coupled to a superconducting resonator

Yusef Maleki and Aleksei Zheltikov

Doc ID: 346341 Received 19 Sep 2018; Accepted 04 Dec 2018; Posted 14 Dec 2018  View: PDF

Abstract: We show that a hybrid quantum device consisting of three ensembles of nitrogen--vacancy (NV) centers whose spins are collectively coupled to a superconducting coplanar waveguide resonator enables the generation of controllable macroscopic tripartite entangled states. At the instants of time when the waveguide resonator is completely depleted of photons and is thus disentangled from the NV-center ensembles, macroscopic Greenberger--Horne--Zeilinger-type states are generated in NV-diamond memories.

Double-layer Fano resonance photonic crystal slabs based sensor for label-free detection of different sizes analytes

Zheng Wang, Chao Wang, Fujun Sun, Zhongyuan Fu, Zekun Xiao, Jiawen Wang, and Huiping Tian

Doc ID: 346189 Received 17 Sep 2018; Accepted 04 Dec 2018; Posted 04 Dec 2018  View: PDF

Abstract: We propose a double-layer Fano resonance photonic crystal (PhC) slabs based sensor (DFRPhCS) for label-free detections. One of the slabs is fully etched, while the other is partially etched, with three resonant dips in the transmission spectrum, which can detect and distinguish different size analytes. As for bulk detection, all three resonant dips show red shifts, with refractive index (RI) of the environment increasing, achieving a sensitivity of 800nm/RIU (refractive index unit) and detection limitation of 1.71×10-7 RIU, respectively. For the detection of micron level particles, due to the large analyte sizes, molecules will be stuck upon the upper slab, thereby changing the polarity and offset of the middle dip. Moreover, for nanoparticle detections, molecules can easily permeate the air holes, therefore, the solution concentration variations of nanoparticles lead to wavelength shift of the middle dip with polarity remained. Accordingly, the dimension and RI of the analyte can be distinguished, thereby indirectly presuming the category of the analyte. Furthermore, DFRPhCS is promising in preliminary detections and can be improved further by adjusting the angle as well as polarization of the incidence appropriately.

Influence of weak measurement on uncertainty relations in a quantum dissipative system

Guo-Qing Zhang and Jing-Bo Xu

Doc ID: 346931 Received 27 Sep 2018; Accepted 03 Dec 2018; Posted 04 Dec 2018  View: PDF

Abstract: We investigate the influence of weak measurement on the quantum-memory-assisted entropic uncertainty relation and quantum speed limit time in a quantum dissipative system by making use of the hierarchical equations of motion method. It is demonstrated that the weak measurement and measurement reversal can suppress the entropic uncertainty during the evolution of the system and we find a periodical crossover of the quantum speed limit time for different weak measurement strengths which disappears when increasing the coupling strength. Similar influence of the weak measurement on uncertainty relations is then explored at the finite temperature. We also consider the effect of counter-rotating-wave term and show that the rotating-wave approximation is an applicable approximation when studying quantum speed limit time but not appropriate when investigating the quantum-memory-assisted entropic uncertainty relation.

Adverse effect of material absorption on stopped light hollow waveguides with negative index metamaterial cladding

Durdu Guney and Xu Zhang

Doc ID: 345908 Received 14 Sep 2018; Accepted 03 Dec 2018; Posted 04 Dec 2018  View: PDF

Abstract: We theoretically analyze the influence of absorption losses on a hollow waveguide with negative index cladding. The losses modify the waveguide dispersion relations, thereby it has significant effect on the ability to stop the light. The negative index metamaterial cladding with reasonable absorption losses indicate that the losses render the light trapping difficult in such waveguides.

Frequency stabilization of a 650 nm laser to I2 spectrum for trapped 138Ba+ ions

Tian Xie, Naijun Jin, ye wang, Junhua Zhang, Mark Um, Pengfei Wang, and Kihwan Kim

Doc ID: 331944 Received 18 May 2018; Accepted 03 Dec 2018; Posted 04 Dec 2018  View: PDF

Abstract: The optical manipulation of Ba+ ions is mainly performed by a 493 nm laser for the S1/2-P1/2 transition and a 650 nm laser for the P1/2-D3/2 transition. Since the branching ratio between the 493 nm and 650 nm transitions of a single Ba+ ion is comparable, stabilization systems of both lasers are equally important for Doppler cooling, sub-Doppler cooling, optical pumping and state detection. The stabilization system of a 493 nm laser to an absolute Te2 reference has been well established. However, the stabilization of a 650 nm laser has not been presented before. Here we report twenty spectral lines of I2 in the range of 0.9 GHz above the resonance of the P1/2-D3/2 transition. We stabilize the 650 nm laser through the optical cavity to the lowest one among these lines, which is about 350 MHz apart, as the absolute frequency reference. Furthermore, we measure the frequency differences between these iodine lines and the Ba+ resonance through fluorescence excitation spectrum with well-resolved dark states, which is in agreement with the theoretical expectation. The presented stabilization scheme enables us to perform precise experiments with Ba+ ions.

Dynamic Order-reversal Transition in Discrete Time-translational Symmetry Broken Cold Atoms

Geol Moon, Ji-Hyoun Kim, and Wonho Jhe

Doc ID: 342682 Received 20 Aug 2018; Accepted 03 Dec 2018; Posted 04 Dec 2018  View: PDF

Abstract: We experimentally demonstrate order-reversal transition in a discrete time-translational symmetry broken cold atomic system by the application of a pulsed bias-field opposite to the existing order. The reversal transition depends on the strength $h_p$ and the duration $\Delta t$ of the applied pulse, Consequently, we obtain a $h_p-\Delta t$ phase boundary with a divergent relaxation time $\tau$ due to the critical slowing down behavior. Interestingly, the dependence of the dynamic phase boundary and relaxation time on the noise-induced switching rate implies that the system is out of equilibrium, but not in the Ising model of a spin system.

Dispersion trimming for mid-infrared supercontinuum generation in a hybrid chalcogenide/silicon-germanium waveguide

Alberto Della Torre, Milan Sinobad, Barry Luther-Davies, Pan Ma, Stephen Madden, Sukanta Debbarma, Khu Vu, David Moss, Arnan Mitchell, Jean-Michel Hartmann, Jean-Marc FEDELI, Christelle Monat, and Christian Grillet

Doc ID: 348366 Received 15 Oct 2018; Accepted 03 Dec 2018; Posted 05 Dec 2018  View: PDF

Abstract: We report a simple post-process technique that harnesses a hybrid chalcogenide/silicon-germanium system for the control of waveguide dispersion. By adding a chalcogenide top cladding to a SiGe/Si waveguide, we can substantially change the dispersive properties, which underpin the generation of supercontinuum. In our particular example, we experimentally show that a shift from anomalous to normal dispersion takes place. We numerically study the dispersion dependence on the chalcogenide thickness and show how to use this additional degree of freedom to control the position of the zero dispersion wavelengths, and hence the spectral span of the supercontinuum. Finally, we compare our approach with more traditional techniques that use geometry for dispersion tailoring.

Analysis of the angular spectrum for ultrashort laser pulses

Jeffrey Brown, Arnaud Couairon, Pavel Polynkin, and Mette Gaarde

Doc ID: 347042 Received 01 Oct 2018; Accepted 03 Dec 2018; Posted 04 Dec 2018  View: PDF

Abstract: We present a practical diagnostic for quantifying the changes to the supercontinuum spectrum of an ultrashort laser pulse undergoing nonlinear propagation. The method allows a connection to be made between a nonlinear physics phenomenon and the specific regions of the angular spectrum that it affects. We apply this method to investigate interference between the third harmonic generation and self-phase modulation.

Dual Frequency Comb Photon Echo Spectroscopy

Jonggu Jeon, JunWoo Kim, Tai Hyun Yoon, and Minhaeng Cho

Doc ID: 347339 Received 02 Oct 2018; Accepted 02 Dec 2018; Posted 04 Dec 2018  View: PDF

Abstract: Dual frequency comb (DFC) nonlinear spectroscopy is an emerging technique that can be used to study a variety of molecular nonlinear responses by exploiting the automatic pulse-to-pulse time delay scanning and fast data acquisition characteristics of the DFC techniques. Here, we propose a DFC-based photon echo spectroscopy (DFC-PES), where two optical frequency comb (OFC) lasers are allowed, in general, to have different carrier frequencies and pulse repetition rates. We first demonstrate our theoretical approach for the DFC linear spectroscopy. Then, the signals expected from the proposed DFC-PES are theoretically calculated. The slight offset in the pulse repetition rates enables the asynchronous optical sampling and the automatic scanning of the time intervals between different field-matter interaction events, making frequency tuning unnecessary. Analytic expression of the third-order photon echo signal is demonstrated in two frequency dimensions for a simple two-level model system. The signal has a well-defined and simple connection to the underlying third-order response function and exhibits the expected down-conversion features from the optical frequency into the radio frequency region with a down conversion factor that is experimentally controllable.

Coherent supercontinuum generation in tellurite glass regular lattice photonic crystal fibers

Mariusz Klimczak, Damian Michalik, Grzegorz Stepniewski, Tanvi Karpate, Jarosław Cimek, Xavier Forestier, Rafal Kasztelanic, Dariusz Pysz, Ryszard Stepien, and Ryszard Buczynski

Doc ID: 347041 Received 01 Oct 2018; Accepted 02 Dec 2018; Posted 04 Dec 2018  View: PDF

Abstract: We report on designing, fabrication and linear as well as nonlinear characterization of highly nonlinear, tellurite glass photonic crystal fibers with engineered normal dispersion characteristics for coherent supercontinuum generation. Effectively single mode air-hole lattice fibers, with measured, all-normal dispersion profiles as flat as -10 to -50 ps/mn/km over 1500-2400 nm wavelengths are developed and investigated. Supercontinuum spectra are measured for these fibers, with a record spectral width covering 1100-2600 nm wavelengths under pumping with a robust, fixed-wavelength erbium fiber-based femtosecond laser, delivering 90 fs pulses, centered at 1560 nm with peak power below 40 kW. To the best of our knowledge, this is the record spectral width of a self-phase modulation and optical wave breaking-based, all-normal dispersion supercontinuum, pumped with a small foot-print, turn-key femtosecond laser.

Femtosecond laser filaments in dissipative plasmonic liquids: supercontinuum and ultrasonic tracing

Sergey Kudryashov, Andrey Samokhvalov, Yuri Geints, Edyard Ageev, and Vadim Veiko

Doc ID: 345290 Received 07 Sep 2018; Accepted 01 Dec 2018; Posted 04 Dec 2018  View: PDF

Abstract: Focused 100-fs, 800-nm laser pulses with variable supercritical peak powers fragmented into multiple mm-long filaments (super-filamentation regime) in pure water and Au-nanoparticle hydrosols of variable extinction coefficients. Power-dependent supercontinuum acquired at the blue shoulder of the laser pulses, overlapped with the Au-nanoparticle plasmon resonance and as a result was damped by two orders of magnitude. The damping factor increased versus the increasing Au-nanoparticle extinction through dissipative linear absorption of both the supercontinuum emission and pump-pulse attenuation in the colloidal solutions, with the latter process damping the underlying 3-interactions in the filaments. The minor optical extinction of the Au nanoparticles at the 800-nm pump wavelength pertained the filamentation process, with the corresponding dissipative losses ultrasonically probed via thermoacoustic generation mechanism in terms of peak laser power, exhibiting the third power for the pure water and diluted Au-nanoparticle hydrosols, and the second power for the more concentrated ones.

Signal-Dependent Pump to Probe Noise Transfer Due to Kerr Nonlinearity in Silicon Ring Resonators

Tomer Yeminy, Zeev Zalevsky, and Dan Sadot

Doc ID: 345296 Received 07 Sep 2018; Accepted 29 Nov 2018; Posted 30 Nov 2018  View: PDF

Abstract: The pump-probe configuration has been extensively implemented in silicon ring resonators (RRs) for all-optical switching and wavelength conversion. While the pump's influence on probe's signal is well known, the effect of the pump on the probe's noise has not been studied. Here, we analytically and numerically analyze the impact of the pump's signal and noise on the probe's noise distribution. We show that the probe's output noise has two sources: the probe's input noise passing through the RR's transfer function, and a new noise term generated by the RR's transfer function fluctuations caused by the pump's noise via Kerr effect. Furthermore, this pump-induced noise can significantly reduce the probe's output optical signal to noise ratio (OSNR) by up to 15dB. As the new noise term strongly depends on the pump's power, wavelength conversion of optical communications signals with high order modulation formats will result in considerable signal-dependent noise, which can greatly affect the receiver's design and performance. In addition, the developed probe noise model can be used to design low noise wavelength converters and switches employing silicon Kerr RRs.

Investigation of supercontinuum generated in the cladding of highly nonlinear photonic crystal fiber

Julius Vengelis, Vygandas Jarutis, Marius Franckevičius, Vidmantas Gulbinas, and Valdas Sirutkaitis

Doc ID: 346064 Received 17 Sep 2018; Accepted 28 Nov 2018; Posted 29 Nov 2018  View: PDF

Abstract: We present experimental and numerical investigation of supercontinuum generation in polarization-maintaining highly nonlinear photonic crystal fiber using subnanosecond pulses of a passively Q-switched Nd:YAG microlaser. For analysis of temporal and spectral characteristics we performed spectrogram measurements using streak camera. Supercontinuum spectrograms revealed presence of cladding modes in our photonic crystal fiber and showed that part of supercontinuum light was actually generated in the cladding modes. Moreover, numerical simulations indicated that distinct cladding modes can exhibit different dispersion which adds more complexity to supercontinuum generation processes.

Few-cycle, carrier-envelope-phase-stable laser pulses from a compact supercontinuum source

William Putnam, Phillip Keathley, Jonathan Cox, Andreas Liehl, Alfred Leitenstorfer, and Franz Kaertner

Doc ID: 345910 Received 14 Sep 2018; Accepted 25 Nov 2018; Posted 28 Nov 2018  View: PDF

Abstract: We report on a few-cycle, carrier-envelope-phase-stable laser source based on supercontinuum generation driven by an amplified Er:fiber-based system. Seed pulses from the Er:fiber system generate a stable supercontinuum in a highly nonlinear optical fiber, and the short and long wavelength tails of this continuum are used in an f-to-2f interferometer to stabilize the carrier-envelope phase (CEP) of the Er:fiber seed via an acousto-optic modulator. Compressing the central part of the continuum, we generate a train of CEP-stabilized laser pulses with a central wavelength of 1170 nm, a duration of 9.1 fs (~2.3 optical cycles), and a repetition rate of 78.4 MHz. Characterizing the CEP stability of our output pulse train with an out-of-loop f-to-2f interferometer, we find a phase jitter of only 157.4 mrad when integrating the radiofrequency spectrum from 5 mHz to 5 MHz.

Recent advances in PNR SSPD: Moving towards high-efficiency

MARIA MOSHKOVA, Alexander Divochiy, Pavel Morozov, Yury VAKHTOMIN, ANDREY ANTIPOV, Philipp Zolotov, Vitaly Seleznev, Marat Ahmetov, and Konstantin Smirnov

Doc ID: 347075 Received 01 Oct 2018; Accepted 24 Nov 2018; Posted 26 Nov 2018  View: PDF

Abstract: The use of improved fabrication technology, highly disordered NbN thin films and intertwined section topology makes possible to create photon number resolving superconducting single photon detectors (PNR SSPD) with comparable to conventional single-element SSPD characteristics in telecom range. Developed 4-section PNR SSPD has simultaneously 86% ±3% system detection efficiency, 35 cps dark count rate, ~2 ns dead time and maximum 90 ps jitter. An experimental investigation of detection efficiency of multi-photon events shown good uniformity across sections. As a result, such PNR SSPD is good candidate for application in retrieving photon statistics of light sources and in QKD systems

Dynamical Quantum Steering in Pulsed HybridOpto-Electro-Mechanical System

Tesfay Gebremariam Tesfahannes, Mojtaba Mazaheri, Yexiong Zeng, and Chong Li

Doc ID: 342940 Received 27 Aug 2018; Accepted 24 Nov 2018; Posted 26 Nov 2018  View: PDF

Abstract: We have investigated the dynamical entanglement and quantum steering in a pulsed hybrid electro-optomechanicalsystem. Using the symmetric and asymmetric criteria, the possibility of bipartite entanglement,one-way steering, two-way steering and collective tripartite steering have been studied betweendifferent output modes. In addition, the influence of squeezing interaction time parameter on the amountof tripartite steering measurement is also examined. The results show that the higher electro-mechanicalcoupling rate leads to a stronger tripartite steering. The microwave cavity mode can enhance the outputquantum steering and remotely steers the optical cavity, on the other words, the slower mode steers thefaster mode. Such hybrid systems can be served as frequency converters between microwave and opticaldomains, and can be profound impact on building quantum networks of microwave-operated superconductingquantum computers.

Enhancing quantum entanglement by asymmetric combinations of photon additions and subtractions

Yang Yang

Doc ID: 343009 Received 24 Aug 2018; Accepted 23 Nov 2018; Posted 26 Nov 2018  View: PDF

Abstract: We investigate the problem of enhancing quantum entanglement of the two-mode squeezed vacuum state by asymmetric combinations of photon additions and subtractions. Suppose a combination of $N$ operations is performed on the two-mode squeezed vacuum state, in which each operation may be either photon addition or photon subtraction and may be performed on either mode $A$ or mode $B$ of the state, then there are $(N+1)2^N$ possible combinations in all. We calculate in detail the entanglement enhancement by all possible combinations for each given $N \in \{1,2,\cdots,5,6\}$ respectively, and find that when the squeezing parameter is small, combinations such as $aa^{\dag}aa^{\dag}\cdots$, $a^{\dag}aa^{\dag}a\cdots$ and their equivalent ones always achieve the greatest enhancement of entanglement, while combinations such as $aaaa\cdots$, $a^{\dag}a^{\dag}a^{\dag}a^{\dag}\cdots$ and their equivalent ones always achieve the least enhancement of entanglement; when the squeezing parameter is great enough, entanglement enhancement by each combination is nearly the same. We also compare the maximal and minimal entanglement achieved by such combinations for $N=1-6$, and find that when the squeezing parameter is small, a combination of more operations may generate even less entanglement than a combination of fewer operations.

The coupling of optical Cherenkov radiation to carbon nanotubes in athree-dimensional compound medium

Gennadiy Burlak and Gustavo Medina-Angel

Doc ID: 345599 Received 17 Sep 2018; Accepted 22 Nov 2018; Posted 26 Nov 2018  View: PDF

Abstract: We systematically study the optical Cherenkov radiation in a compoundthree-dimensional (3D) system with a charge moving over a periodic system of parallel carbon nanotubes. To consider a case of bounded single-wallednanotubes we apply the numerical FDTD technique. We found that, because of the broadband radiation of a charge the spectrum of the optical field in such a nanosystem is determined by the surface plasmon-polariton excitations. This leads to a significant dependency of the field energy on the plasma frequency of nanotubes. Our study of the field energy spectrum as a function of the plasma frequency discovers a non-monotonic double-well dependency within the area of a surface plasmon-poliariton resonance. It is found a well defined peak that indicates a coupling of the Cherenkov field to the collective excitations in a nanotube structure. Such an effect can allow controlling the optical emission of nanotube structures in micro- and nanoscale.

Ultra-Broadband Wide-Angle Perfect Absorber in Visible through Thin Grating-Insulator-Metal Structures

Chen Xu, Jiuhui Wu, ChongRui Liu, and Pei Cao

Doc ID: 347100 Received 01 Oct 2018; Accepted 21 Nov 2018; Posted 26 Nov 2018  View: PDF

Abstract: A new thin grating-insulator-metal (GIM) structure with ultra-broadband wide-angle perfect absorption is proposed, and a general approach to this kind of multilayered structure is investigated based on the rigorous coupled wave analysis method and the transfer matrix method. On the basis of this approach, the electromagnetic field distributions in each layer and optical diffraction coefficients are derived theoretically. Compared with a metal-insulator-metal (MIM) structure, the GIM structure consisting of a metal grating on top of a low-loss dielectric layer and a bottom metal layer can achieve a higher absorption with the smaller thickness that attributes to the extraordinary optical transmission of top grating layer and the cavity resonance of middle insulator layer. By optimizing the structural and material parameters, the materials from top to bottom are selected as Mn-Al2O3-Mn, whose thicknesses are 10 nm, 65 nm and 70 nm, respectively. With these optimum parameters, the better performance with the average absorption over 95% in the visible regime is obtained. Furthermore, this structure still retains the near-perfect broadband absorption for large incidence angles and different polarizations. The conclusions presented here could have potential applications in optical devices such as optical displacement detection and visible light absorption.

Four-wave mixing response in a hybrid atom-optomechanical system

Bin Chen and Xiao-Fang Wang

Doc ID: 345847 Received 19 Sep 2018; Accepted 21 Nov 2018; Posted 29 Nov 2018  View: PDF

Abstract: We study the four wave mixing (FWM) effect in a hybrid optomechanical system, which is comprised of an ensemble of two-level atoms trapped inside an optical cavity with a moving end mirror, and mainly focus on the response of the FWM on the atomic media. The numeric results show that the FWM signal can be enhanced effectively by coupling the optical cavity to the atom ensemble. With the increase of the atom-cavity coupling strength, the FWM intensity can be increased significantly. More interestingly, the FWM signal can be easily switched on or off for zero probe-pump detuning case just by tuning the atom-pump detuning to be positive or negative, and the FWM intensity can also be effectively modulated by controlling the atom-pump detuning. The obtained results may have potential applications in all-optical wavelength convertor, all-optical switches or other optical devices.

On-chip correlation-based Brillouin sensing: design, experiment and simulation

Atiyeh Zarifi, Birgit Stiller, Moritz Merklein, Yang Liu, Blair Morrison, Alvaro Casas-Bedoya, Guanghui Ren, Thach Nguyen, Khu Vu, Duk-Yong Choi, Arnan Mitchell, Stephen Madden, and Benjamin Eggleton

Doc ID: 344338 Received 30 Aug 2018; Accepted 20 Nov 2018; Posted 21 Nov 2018  View: PDF

Abstract: Wavelength-scale SBS waveguides are enabling novel on-chip functionalities. The micro- and nano-scale SBS structures and the complexity of the SBS waveguides require a characterization technique to monitor the local geometry-dependent SBS responses along the waveguide. In this work, we experimentally demonstrate detection of longitudinal features down to 200 μm on a silicon-chalcogenide waveguide using the Brillouin optical correlation analysis (BOCDA) technique. We provide extensive simulation and analysis of how multiple acoustic and optical modes and geometrical variations influence the Brillouin spectrum.

Full statistics of ideal homodyne detection using real (noisy) local oscillator

Adriana Auyuanet, Eugenia Benech, Horacio Failache, and Arturo Lezama

Doc ID: 345889 Received 14 Sep 2018; Accepted 19 Nov 2018; Posted 21 Nov 2018  View: PDF

Abstract: We show that the full statistics of the two detectors outputs in a balanced homodyne detection setup involving a local oscillator in an ideal coherent state is experimentally accessible despite the excess noise existing in actual laser sources. This possibility is illustrated using phase randomized coherent states signals from which the statistics of Fock states can accurately be obtained. The experimental verification of the recently predicted \cite{kuhn18} two-detector correlation probability for Fock states is presented for states $\vert 1 \rangle$ and $\vert 2 \rangle$.

Third harmonic generation from regularized converging filaments

Daniil Shipilo, Daria Mokrousova, Nikolay Panov, Georgy Rizaev, Anna Shalova, Elena Sunchugasheva, Andrey Ionin, Arnaud Couairon, Leonid Seleznev, and Olga Kosareva

Doc ID: 345963 Received 17 Sep 2018; Accepted 19 Nov 2018; Posted 20 Nov 2018  View: PDF

Abstract: The square-like angular distribution of the third harmonic generated along the four regularized 744-nm filaments was observed experimentally and reproduced in 3D+time numerical simulations. Fusion and superfilament formation from the initially separated filaments arrests the third harmonic yield but produces the fourfold increase in the blue wing of the fundamental and the third harmonic supercontinuum. This demonstrates the opposite effect of superfilamentation on the nonlinear phenomena requiring the sufficient coherence length or the intense localized response.

High power mid infrared supercontinuum generation in multimode fluoride fiber

Zahra Eslami, Piotr Ryczkowski, Caroline Amiot, lauri SALMELA, and Goëry Genty

Doc ID: 347223 Received 01 Oct 2018; Accepted 19 Nov 2018; Posted 20 Nov 2018  View: PDF

Abstract: We demonstrate the generation of octave-spanning supercontinuum (SC) generation from 1.2 µm to over 2.5 µm with 600 mW average power in a short length of multimode fluoride fiber with 100 µm core diameter. We perform a detailed study of the SC generation as a function of the pump wavelength and for different fiber lengths. Beam profile characterization at the fiber output in different wavelength bands is also carried out. Our results open up new possibilities for the generation of high-power supercontinuum sources in the near/mid-infrared.

The role of external focusing geometry in supercontinuum generation in bulk solid-state media

Vytautas Jukna, Nail Garejev, Gintaras Tamosauskas, and Audrius Dubietis

Doc ID: 344971 Received 05 Sep 2018; Accepted 18 Nov 2018; Posted 19 Nov 2018  View: PDF

Abstract: We present a detailed experimental and numerical study of supercontinuum generation in sapphire crystal at the vicinity of its zero group velocity dispersion point (1.3 μm) as pumped by relatively long (210 fs) femtosecond pulses. We uncover very different evolutions of the spectral broadening versus the input pulse energy when the incident beam is focused either onto the input face or inside 4 mm-thick sapphire sample. In particular, when the input beam was focused inside the crystal, we captured a surprising variation of the spectral width as a function of the input pulse energy, demonstrating supercontinuum generation, its suppression and eventually, its recovery. The experimental findings were nicely reproduced by the numerical simulations,revealing a specific supercontinuum generation scenario, which relies on strong reshaping of the wave packet due to defocusing and absorption of free electron plasma, subsequent replenishment of the pulse on the propagation axis and its splitting. We also demonstrate that this particular supercontinuum generation scenario takes place regardless of the external focusing geometry although manifests itself to slightly a different extent in terms of the observed spectral evolution.

Pulse-to-pulse instabilities in synchronously pumped femtosecond optical parametric oscillator

Karolina Ivanauskienė, Ignas Stasevicius, Mikas Vengris, and Valdas Sirutkaitis

Doc ID: 346804 Received 27 Sep 2018; Accepted 18 Nov 2018; Posted 19 Nov 2018  View: PDF

Abstract: We report the investigation of periodic instabilities in synchronously pumped femtosecond optical parametric oscillator (OPO). Steady-state operation is observed at moderate pumping levels, whereas complex spectral behaviour manifests as pumping power is increased. Nontrivial role of group delay dispersion in the origin of pulse-to-pulse instabilities is observed. Sequences of single pulse spectra are recorded showing energy repartition between separate spectral components. Relation between pump power and resonator's group delay dispersion is investigated experimentally and numerically.

Methods of decreasing the unambiguous state discrimination probability for subcarrier wave quantum key distribution systems

Andrei Gaidash, Anton Kozubov, and George Miroshnichenko

Doc ID: 347056 Received 28 Sep 2018; Accepted 18 Nov 2018; Posted 19 Nov 2018  View: PDF

Abstract: In this paper we compare two solutions (well-known and new proposed) for subcarrier wave quantum key distribution systems which decreases crucial impact of the unambiguous state discrimination attack in order to ensure security in channels with higher losses.One of the well known methods is based on adding more signal states and allows to decrease the probability of successful discrimination. However sifting fraction will decrease too leading to lower key rates. Thus we propose the technique which utilizes additional vacuum (unmodulated) state with low a priori sending probability and provides the same decrease (in the first order) of unambiguous discrimination as for four signal states however maintaining sifting fraction as for two states.

Multi-spectral photoacoustic sensing foraccurate glucose monitoring usingsupercontinuum laser

Manoj Kumar Dasa, Christos Markos, Jakob Janting, and Ole Bang

Doc ID: 347429 Received 08 Oct 2018; Accepted 16 Nov 2018; Posted 16 Nov 2018  View: PDF

Abstract: Accurate monitoring of glucose levels constitutes the most important parameter for diabetes management and treatment planning. In this work, we report on an in vitro glucose monitoring system based on multi-spectral photoacoustic sensing (MSPAS) using a cost-effective supercontinuum (SC) laser. We demonstrate for the first time, to the best of our knowledge, how the use of a broadband SC source allows the identification of distinct absorption characteristics of two major analytes (glucose and cholesterol) present inside the human body in the extended near-infrared (NIR) 1540-1840 nm spectral range. Employing the reported SC-based MSPAS system with a ratiometric analysis; we were able to accurately (coefficient of determination > 0.938) measure a wide range of glucose concentration levels in vitro. We further demonstrate clinically accurate prediction of glucose concentrations over commonly encountered physiological levels inside the human body (0 to 400 mg/dL) with respect to the Clarke error grid (CEG) analysis. These findings pave way for devising of potential non-invasive and label-free continuous glucose monitoring systems.

Theoretical analysis of tuning property of the graphene integrated excessively tilted fiber grating for sensitivity enhancement

Zhihong Li, Zhuying Yu, Boteng Yan, Xiukai Ruan, Yaoju Zhang, and Yuxing Dai

Doc ID: 346268 Received 18 Sep 2018; Accepted 15 Nov 2018; Posted 15 Nov 2018  View: PDF

Abstract: The graphene integrated optical fiber devices show many excellent characteristics, especially their tunable optical properties. Here we investigate thoroughly the influence of tuning property of the graphene on the resonance and sensing performance of the excessively tilted fiber grating (Ex-TFG) operating around the dispersion-tuning-point (DTP). An improved piecewise discretization method for the finite-difference mode solver combined with coupling mode theory is presented to explore the general variation rule of mode characteristics and polarization-dependent resonances corresponding to polarized TE/TM0,m and HE/EHv,m modes of the graphene integrated Ex-TFG. The results reveal that both p-polarized and s-polarized modes and their resonances are greatly influenced by the tunable graphene. On this basis, the sensitivity enhancement of the graphene coated Ex-TFG is explored in detail. It is shown that the sensing performance of both polarized cases can be greatly improved by tuning the chemical potential. In particular, the graphene induces a greater influence on both resonance wavelength and resonance strength of the s-polarized mode but the p-polarized one has a higher sensitivity. We believe that these unique tuning properties make the graphene integrated Ex-TFG devices ideal for the telecommunication and sensing applications, such as tunable fiber modulators and bio-chemical sensors.

Experimental observation of three-photon superbunching with classical light in linear system

Yu Zhou, Sheng Luo, Zhaohui Tang, Huaibin Zheng, Hui Chen, Jianbin Liu, fuli li, and Zhuo Xu

Doc ID: 347804 Received 09 Oct 2018; Accepted 15 Nov 2018; Posted 15 Nov 2018  View: PDF

Abstract: Three-photon superbunching is experimentally observed with the recently proposed superbunching pseudothermal light. To the best of our knowledge, it is the first time that three-photon superbunching is observed with classical light in a linear optical system. From the quantum optics point of view, three-photon superbunching is interpreted as the result of constructive-destructive three-photon interference. The key to observe three-photon superbunching with superbunching pseudothermal light is that all the different ways to trigger a three-photon coincidence count are in principle indistinguishable, which is experimentally guaranteed by putting a pinhole before each rotating groundglass to ensure that all the passed photons are within the same coherence area. The observed three-photon superbunching is helpful to increase the visibility of ghost imaging and understand the physics of third-order interference of light.

Poor-man's model of hollow-core anti-resonant fibers

Morten Bache, Md Selim Habib, Christos Markos, and Jesper Laegsgaard

Doc ID: 345687 Received 12 Sep 2018; Accepted 15 Nov 2018; Posted 15 Nov 2018  View: PDF

Abstract: We investigate various methods for extending the simple analytical capillary model to describe the dispersion and loss of anti-resonant hollow-core fibers without the need of detailed finite-element simulations across the desired wavelength range. This poor-man's model can with a single fitting parameter quite accurately mimic dispersion and loss resonances and anti-resonances from full finite-element simulations. Due to the analytical basis of the model it is easy to explore variations in core size and cladding wall thickness, and should therefore provide a valuable tool for numerical simulations of the ultrafast nonlinear dynamics of gas-filled hollow-core fibers.

Characteristics of Light–Plasmon Coupling on Chiral–Graphene Interface

Muhammad Yaqoob, Abdul Ghaffar, Majeed Alkanhal, and Sajjad rehman

Doc ID: 345431 Received 10 Sep 2018; Accepted 14 Nov 2018; Posted 15 Nov 2018  View: PDF

Abstract: : This theoretical study has been carried out on the characteristics of light–plasmon coupling on the chiral–graphene interface. The graphene’s conductivity is modeled in the framework of Kubo’s formulism. The impedance boundary condition approach is used to compute the dispersion relationship for the chiral–graphene interface and dispersion curve analysis is used to study the light–plasmon coupling in the chiral–graphene interface. This study concludes that the chiral–graphene interface supports the hybrid surface plasmon modes, i.e. the upper and lower modes that can be used to sense the chirality and chemical sense biochemical molecules. Furthermore, this study presents the influence of chirality (ξ), chemical potential (μg), and layers of graphene (N) on the dispersion relation, propagation length (Lp), and effective mode index (Neff), and it concludes that both the chiral and graphene parameters can be used to tune the plasmonics resonance frequencies. This study presents the cut-off chiral value (ξc) as a function of the frequency (ω) under different values of chemical potential (μg) and index of refraction (nc) and the numerical results revealed that light–plasmon coupled modes are exploitable for on-chip chiral sensing and enantiomeric detection applications.

Reference pulse attack on continuous variable quantum key distribution with local local oscillator under trusted phase noise

Shengjun Ren, Rupesh Kumar, Adrian Wonfor, Xinke Tang, Richard Penty, and Ian White

Doc ID: 347079 Received 01 Oct 2018; Accepted 14 Nov 2018; Posted 15 Nov 2018  View: PDF

Abstract: We show that partially trusting the phase noise associated with estimation uncertainty in a LLO-CVQKD system allows one to exchange higher secure key rates than in the case of untrusted phase noise. However, this opens a security loophole through the manipulation of the reference pulse amplitude. We label this as ‘reference pulse attack’ which is applicable to all LLO-CVQKD systems if the phase noise is trusted. We show that, at the optimal reference pulse intensity level, Eve achieves unity attack efficiency at .8km and 32.0km while using lossless and 0.14dB/km loss channels, respectively, for her attack. However, in order to maintain the performance enhancement from partially trusting the phase noise, countermeasures have been proposed. As a result, the LLO-CVQKD system with partially trusted phase noise owns a superior key rate at 20km by an order 9.5, and extended transmission distance by 45%, than that of the phase noise untrusted system.

Scaling power, bandwidth, and efficiency of mid-infrared supercontinuum source based on a GeO2 doped silica fiber

Deepak Jain, Ole Bang, Seongwoo Yoo, Raghuraman Sidharthan, Peter Moselund, patrick bowen, and Getinet Woyessa

Doc ID: 345937 Received 05 Oct 2018; Accepted 13 Nov 2018; Posted 15 Nov 2018  View: PDF

Abstract: We demonstrate a supercontinuum source with a 20 dB bandwidth from ~1 µm to ~3 µm with output power exceeding 6 W based on a GeO2 doped silica fiber. This is the highest output power reported for a 3 µm supercontinuum source based on Germania doped silica fiber in an all fiberized and compact size device. We further demonstrate a spectrum spanning from ~1.7 µm to ~3.4 µm (~10 dB bandwidth from ~1.8 µm to ~3.2 µm) at a low power of tens of mw with more than 50 % power fraction above 2400 nm, which makes this source suitable for several application where a broadband source at low power is required to avoid damage of the samples. Our investigations reveal the unexploited potential of Germania doped fiber for mid-infrared supercontinuum generation and surpasses the current state-of-the-art results.

Zeroth-order continuous vector frozen waves for light scattering: exact multipole expansion in the generalized Lorenz-Mie theory

Leonardo Ambrosio, Michel Zamboni-Rached, and Gerard Gouesbet

Doc ID: 340968 Received 30 Jul 2018; Accepted 13 Nov 2018; Posted 15 Nov 2018  View: PDF

Abstract: In this paper we theoretically investigate the exact beam shape coefficients of a specific and promising class of nondiffracting light waves for optical trapping and micro-manipulation known as continuous vector Frozen Waves (CVFWs). CVFWs are constructed from vector Bessel beams in terms of a continuous superposition (integral) over the longitudinal wave number, the final longitudinal intensity pattern being determined through the specification of a given spectrum S(kz). The incorporation of such highly confined and micro-structured fields into the theoretical framework of the generalized Lorenz-Mie theory (GLMT) is a first step towards the integration of such beams with optical tweezers systems as potential laser beams for the multiple manipulation of micro- and nano-particles along their optical axis and in multiple transverse planes. Linear, azimuthal and radial polarizations are considered, the BSCs being calculated using three distinct approaches. The results extend and complete previous works on discrete FrozenWaves for light scattering problems with the aid of the GLMT.

The magnitude of the Goos-Hanchen shift depends on the beam propagation in a medium

Zia uddin, Ghais uddin, Muqadder Abbas, and Li Wang

Doc ID: 342576 Received 17 Aug 2018; Accepted 13 Nov 2018; Posted 15 Nov 2018  View: PDF

Abstract: We study the Goos-H$\ddot{\text a}$nchen shift (GHS) in the reflected light (RL) by considering one-dimensional double-layered structure. The double-layered structure consists of dielectric slabs having gain-loss properties. A Gaussian beam is incident on a double-layered structure, making an angle $\theta$ with $z$ axis. Positive GHS in the RL are investigated for different incident angles when both the layers have gain property. Similarly, negative GHS in the RL are investigated for different incident angles by considering loss in both layers. By considering the gain in one layer and equal amount of loss in another, we achieved giant negative GHS in the RL. Interestingly, we develop the connection of magnitude of the GHS and light beam propagation through the medium and show that the magnitude of the GHS in the RL dependents on the light beam propagation through the medium. Giant negative GHS in the RL are achieved for a Gaussian beam that propagates more into the medium. The greater the penetration of an incident beam in the medium greater will be the magnitude of the GHS in the RL and vice versa.

A Reconfigurable Multi-Party Quantum Network Enabled by a Broadband Entangled Source

Eric Zhu, Costantino Corbari, Alexey Gladyshev, Peter Kazansky, Hoi-Kwong Lo, and Li Qian

Doc ID: 347221 Received 02 Oct 2018; Accepted 12 Nov 2018; Posted 12 Nov 2018  View: PDF

Abstract: We present a proof-of-principle experimental demonstration of a reconfigurable, multi-party quantum key distribution (QKD) scheme utilizing a poled fiber-based source of broadband polarization-entangled photon pairs and dense wavelength-division multiplexing (DWDM). The large bandwidth (> 90 nm centered about 1555 nm) and highly spectrally-correlated nature of the entangled source can be exploited to allow for the generation of more than 25 frequency-conjugate entangled pairs when aligned to the standard 200-GHz ITU grid. In this work, 3 frequency-conjugate entangled pairs are used to demonstrate QKD, with wavelength-selective switching done manually. The entangled pairs are delivered over 40 km of actual fiber, and an estimated secure key rate of up to 20 bits/s per bi-party is observed.

Functionalizing plasmonic nanoparticles through adding a shell to improve electrical properties of c-Si thin-film solar cells

Mandana Jalali, Tahmineh Jalali, Hamid Nadgaran, and Daniel Erni

Doc ID: 344468 Received 28 Aug 2018; Accepted 10 Nov 2018; Posted 16 Nov 2018  View: PDF

Abstract: Embedding plasmonic nanoparticles (p-NPs) inside the solar cell's active layer is capable of enhancing active layer optical absorption, however such inclusion has some detrimental effects on the electrical properties of the solar cells. In addition p-NPs are highly catalytic, their presence enables other non-radiative decay channels besides generation of electron-hole pairs, and the electrons usually get absorbed by these p-NPs. This results in the unfavorable fact that the potential enhancement in the carrier generation rate and the generated current is no more in line with the enhancement in the optical absorption. In this paper, we propose to functionalize p-NPs by adding a dielectric or semiconductor shell, to passivate the p-NP without deteriorating scattering and/or plasmonic effects. Ag@SiO2 and Ag@TiO2 core-shell p-NPs have been intensely studied using extensive computational electromagnetic simulations to model the spectral response of the active layer's optical absorption as well as electrical properties as a function of both shell composition and thickness. It is shown that a 5nm TiO2 shell is apt to optically passivate the p-NP without any reduction in optical absorption, while improving the short circuit current density (Jsc) of the thin-film solar cell by 33.3%.

A model for confined Tamm plasmon devices

Michael Adams, Benjamin Cemlyn, Ian Henning, Matthew Parker, Edmund Harbord, and Ruth Oulton

Doc ID: 344858 Received 03 Sep 2018; Accepted 08 Nov 2018; Posted 08 Nov 2018  View: PDF

Abstract: It is shown that cavities formed between a multilayer quarter-wave Bragg reflector and a metal mirror which support Tamm plasmons can be modelled by using a hard-mirror approximation including appropriate penetration depths into the mirrors. Results from this model are in excellent agreement with those found by numerical methods. In addition Tamm modes that are laterally confined by the presence of a metallic disc deposited on the Bragg reflector can be described by the effective index model that is commonly used for vertical-cavity surface-emitting lasers (VCSELs). This enables the lateral modes confined by a circular disc to be found from conventional weakly-guiding waveguide theory similar to that used for optical fibres. The resonant wavelengths of these linearly-polarised (LP) guided modes are calculated as functions of disc diameter and other parameters.

Millimiter-Structured Nondiffracting Surface Beams

Leonardo Ambrosio

Doc ID: 341101 Received 30 Jul 2018; Accepted 26 Oct 2018; Posted 31 Oct 2018  View: PDF

Abstract: A new type of scalar nondiffracting beam is presented whose main feature is the freedom on the choice of a two-dimensional spatial intesity pattern dependent upon the longitudinal coordinate. Examples of such millimeter-structured surface beams are provided over Cartesian and cylindrical planes and, motivated by the idea of developing beams capable of simultaneous manipulation, guidance and/or trapping of micro- and millimeter-sized particles, here we also derive analytical expressions for their beam shape coefficients in the framework of the generalized Lorenz-Mie theory, a first step towards the analysis of light-matter interactions with spherical particles from such light fields.

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