Abstract

Chalcogenide glasses possess novel optical property in infrared range, which make them ideal candidates for photonic devices by laser direct writing. Precisely control of the refractive index manipulation in the material is the key to achieve high quality optical devices. In this work, diffraction gratings in chalcogenide As2Se3 thin films were fabricated with femtosecond laser direct writing and its refractive index change was carefully studied. Grating diffraction efficiency was measured from visible to near-infrared light by using multiple single-wavelength lasers and a supercontinuum laser. Clear diffraction patterns and high diffraction efficiency indicated the good optical quality of the prepared gratings. Results show that the grating with period of 5 µm inscribed under pulse energy of 30 nJ demonstrated a 1st-order diffraction efficiency of 30% at 808 nm testing wavelength, due to the changes of refractive index and absorption. The relationship of the change of refractive index and absorption coefficient of film under different laser irradiation intensity is carefully studied. The maximum refractive index change was estimated to be 0.087 at 808 nm.

© 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

1. Introduction

Chalcogenide glasses (ChGs) have attracted considerable interest recently not only because of their wide transparency range, high refractive index, and ultrahigh Kerr nonlinearity but also their rich physicochemical properties, such as phase changing and photopolymerization [13]. Given their unique optical properties, ChGs feature widespread applications for thermal imaging, fiber laser, optical communication, and optical sensing in the mid-infrared (MIR) region [46]. Especially, optical devices prepared with ChG films hold the key to functional devices for all-optical processing and bio-sensing of integrated devices in MIR range [78]. Diffraction grating is an important device in spectroscopy due to its capability to separate (disperse) polychromatic light into its constituent monochromatic components [9,10]. Other applications include beam smoothing or microlaser collimation/aberration corrections [1114].

Many approaches, including focused ion beam, soft lithography and laser direct writing, have been developed to prepare diffraction gratings and other optical devices [1518]. Among the manufacturing technologies, laser direct writing features remarkable advantages due to its accurate control of process parameters and capability for arbitrary structure fabrication with sub-diffraction-limited resolution compared with lithographic methods [19]. There have been many studies of the fabrication of chalcogenide gratings with laser writing technology [2023]. C. Meneghini observed two-photon-induced refractive-index changes in As2S3 by exposure in the 800 nm femtosecond laser in 1998, holographic gratings and self-written channel waveguides were also obtained [21]. C. Florea et al. demonstrated of gratings written inside As2S3 glasses and inside optical fibers using an 800 nm femtosecond laser in 2008 [22]. D. Lee et al. studied the fabrication of volume phase gratings and their diffraction efficiency in Ga-La-S glass in 2013 [23]. M.S. El-Bana et al. prepared holographic grating on the surface of As30Se70 film with continuous wave (CW) laser at 532 nm and 633nm in 2016, the change of refractive index and absorption coefficient of the film was obtained with the Swanepoel method [24]. Furthermore, the laser direct writing method was also successfully used in fabrication of photonic crystals, waveguides, and optical fiber gratings with ChGs [2527].

However, ChGs usually present relatively low glass transition temperatures (Tg), such as 185 °C and 178 °C for the commonly used As2S3 and As2Se3 glass, respectively [28,29]. Most ChGs also exhibit absorption in the visible laser range and near-infrared wavelength around 800 nm. In this case, the thermal and optical damage thresholds of ChGs are much lower than traditional oxide glass materials. Therefore, a laser with appropriate intensity must be precisely adjusted to obtain a sufficiently large change in refractive index by laser writing while avoiding material damage. Furthermore, in the design and application of photonic crystals, the refractive index of the material should be accurately known. Therefore, the relationship between refractive index change and laser intensity is a crucial parameter in fabrication of high-quality photonic device with ChGs. However, the changes of the refractive index induced by femtosecond laser in ChGs are usually too small to be directly characterized. The invisibility of the infrared band also increases the difficulty of the measurement. To the best of our knowledge, no systematic research is available on the refractive index change in As2Se3 films with femtosecond laser power and wavelength.

In this study, diffraction gratings in chalcogenide As2Se3 thin films were written by 800 nm femtosecond laser with different power intensities. The laser damage threshold was also estimated by writing a series of single stripes with different laser intensities at an optimized writing speed. Microscope and surface profiler were used to measure the structure morphology. It was observed that the film changed from refractive index modulation to physical damage as the laser intensity increased. The diffraction efficiency of the gratings was measured with continuous wavelength (CW) lasers (808, 980 and 1550 nm) and a supercontinuum (SC) source. The results indicate that the grating inscribed with a laser power of 30 nJ exhibited a 1st-order diffraction efficiency of 30% at 808 nm, and 1.58% at 1550nm. We regards that the large diffraction efficiency at 808 nm is due to the combination of refractive index and absorption change, which was further confirmed by the Swanepoel method [31]. By combining grating diffraction theory and Swanepoel method, the refractive index and absorption coefficient variations under laser irradiation in different laser intensities and wavelengths were finally obtained. Results shown that the maximum refractive index change can be 0.087 at 808 nm, and the calculated diffraction efficiency curve consistented with the experimental results.

2. Theoretical analysis

2.1 Grating diffraction theory

Light will be diffracted into discrete directions when irradiated on a grating surface. The distribution of the diffracted power depends on various parameters, including power and polarization of incident light, angles of incidence and diffraction, and (complex) index of refraction of materials in the grating. Grating thickness also directly influences the diffraction effect. The diffraction efficiency of the prepared grating can be analyzed by the Kogelnik theory [30]. The transmitted intensities I0, refers to the power of transmitted beam from the film without grating and diffracted intensities I1, normalized to incident intensity Ii, which is arisen from the refractive index change and the absorption variation of glasses, are given by the following two equations:

$$ \begin{aligned}\frac{{{\textrm{I}_0}}}{{{\textrm{I}_\textrm{i}}}} &= \textrm{exp}\left( {\frac{{ - \textrm{KH}}}{{\textrm{cos}\alpha }}} \right)\left[ {\textrm{co}{\textrm{s}^2}\left( {\frac{{{\pi }\Delta \textrm{nH}}}{{{\lambda} \textrm{cos}{\alpha }}}} \right) + \textrm{cos}{\textrm{h}^2}\left( {\frac{{\Delta \textrm{KH}}}{{4\textrm{cos}\alpha }}} \right) - 1} \right] \\ \frac{{{\textrm{I}_1}}}{{{\textrm{I}_\textrm{i}}}} &= \textrm{exp}\left( {\frac{{ - \textrm{KH}}}{{\textrm{cos}\alpha }}} \right)\left[ {\textrm{si}{\textrm{n}^2}\left( {\frac{{{\pi }\Delta \textrm{nH}}}{{{\lambda} \textrm{cos}{\alpha }}}} \right) + \textrm{sin}{\textrm{h}^2}\left( {\frac{{\Delta \textrm{KH}}}{{4\textrm{cos}\alpha }}} \right)} \right] \end{aligned} $$
Then diffraction efficiency is defined as follows:
$$ {\eta } = \frac{{{\textrm{I}_1}}}{{{\textrm{I}_0}}} = \frac{{\textrm{si}{\textrm{n}^2}\left( {\frac{{\pi \Delta \textrm{nH}}}{{\lambda \textrm{cos}\alpha }}} \right) + \textrm{sin}{\textrm{h}^2}\left( {\frac{{\Delta \textrm{KH}}}{{4\textrm{cos}\alpha }}} \right)}}{{\textrm{co}{\textrm{s}^2}\left( {\frac{{\pi \Delta \textrm{nH}}}{\lambda {\textrm{cos}}\alpha }} \right) + \textrm{cos}{\textrm{h}^2}\left( {\frac{{\Delta \textrm{KH}}}{{4\textrm{cos}\alpha }}} \right) - 1}} $$
Here K denotes the absorption coefficient, ${\lambda }$ is the wavelength of incident light, and H specifies the effective film thickness. ${\Delta \textrm{n}}$ and ${\Delta \textrm{K}}$ are the changes in the refractive index and the absorption coefficient, ${\alpha }$ is the angle of incidence of the probe beam taken inside the glass, respectively. From Eq. (2), it can be concluded that the diffraction efficiency mainly results from changes in material refractive index and absorption. When operating in the transparent band of the material, the contribution of the absorption variation on the diffraction efficiency is small enough that can be neglected, Eq. (2) can be can be further expressed briefly as follows:
$$ {\eta } = \frac{{{\textrm{I}_1}}}{{{\textrm{I}_0}}} = \frac{{\textrm{si}{\textrm{n}^2}\left( {\frac{{{\pi }\Delta \textrm{nH}}}{{\lambda\textrm{cos}\alpha}}} \right)}}{{\textrm{co}{\textrm{s}^2}\left( {\frac{{{\pi }\Delta \textrm{nH}}}{{\lambda\textrm{cos}\alpha}}} \right)}} = \textrm{ta}{\textrm{n}^2}\left( {\frac{{{\pi }\Delta \textrm{nH}}}{{\lambda\textrm{cos}\alpha}}} \right) $$
$${\Delta \textrm{n}} = \frac{{{\lambda} \textrm{cos}\alpha \sqrt {\textrm{arctan}({\eta } )} }}{{{\pi \textrm{H}}}}$$
By measuring the grating diffraction efficiency, the refractive index modulation induced by the femtosecond laser can be obtained.

2.2 Swanepoel method

In the absorption range of the film, the change of refractive index and absorption coefficient of the film after laser irradiation are difficult to be obtained at the same time with Eq. (2), which can be further studied by Swanepoel method. The Swanepoel method is a useful tool to calculate the refractive index, thickness and absorption coefficient of the films only from their transmission spectrum, which can also achieve an accuracy of higher than 0.5% [31,32]. By measuring the transmission spectrum, the refractive index (n) at each wavelength can be calculated by the following equation:

$$\textrm{n} = \sqrt {2s\frac{{{T_M} - {T_m}}}{{{T_M}{T_m}}} + \sqrt {{{\left( {2s\frac{{{T_M} - {T_m}}}{{{T_M}{T_m}}} + \frac{{{s^2} + 1}}{2}} \right)}^2} - {s^2}} } $$
where s is the substrate refractive index, ${T_M}$ and ${T_m}$ are the upper and lower tangent envelopes of the transmission spectrum, respectively. Furthermore, the film absorption coefficient (α) can calculate by:
$$\textrm{x} = \frac{{\frac{{8{n^2}s}}{{{T_M}}} + ({{n^2} - 1} )({{n^2} - {s^2}} )- \left\{ {{{\left[ {\frac{{8{n^2}s}}{{{T_M}}} + ({{n^2} - 1} )({{n^2} - {s^2}} )} \right]}^2} - {{({{n^2} - 1} )}^3}({{n^2} - {s^4}} )} \right\}}}{{{{({n - 1} )}^3}({n - {s^2}} )}} $$
$${\alpha } ={-} \frac{{lnx}}{{\overline {{d_2}} }}$$
where $\overline {{d_2}} $ represents the average thickness of the film.

3. Experimental details

3.1 Preparation and measurement of As2Se3 thin films

Bulk As2Se3 chalcogenides glasses were prepared from high-purity (5N) elements using melt quenching technique [33,34]. The elements were carefully weighed in a glove box, transferred to quartz ampoules (ϕ = 50 mm), and sealed under a vacuum. The quartz ampoules were heated to 970 °C for approximately 10 h in a rocking furnace to ensure the fusion of elements and homogenization of the melt. The ampoules were quenched in ice water to allow glass formation and avoid crystallization. Finally, the in situ sample inside the sealed silica ampoule was annealed at a temperature slightly below the glass transition temperature before slowly cooling the sample to room temperature.

Thermal evaporation was selected for depositing As2Se3 films on the SiO2 substrates [35]. The substrates were ultrasonically cleaned by acetone and alcohol and then washed by double-distilled water. The As2Se3 thin films were then deposited on the substrates using a JGP-450 coating system. Base pressure was approximately 10−5 Pa, and deposition rate was 14 nm/min. The prepared films were finally annealed at Tg for 2h for better stability. Atomic force microscopy was performed to obtain the surface roughness of the thin film.

A surface profiler (Dektak 150) was used to measure the thickness and surface roughness (Ra) of the films. The thickness of the prepared thin film was 1200 nm, whereas the surface roughness was around Ra = 0.5 ± 0.05 nm. Transparency spectrum of the prepared films was measured in the spectral range of 400 nm to 2000 nm using a PerkinElmer-Lambda 950 UV/VIS/NIR spectrophotometer. Wavelength–refractive index graph was measured by an IR-variable angle spectroscopic ellipsometer (Mark II, J. A. Woollam, USA).

3.2 Laser direct writing of gratings in As2Se3 film

Laser direct writing is a highly flexible technique for the fabrication of arbitrary photonic structures. Figure 1 shows the schematic of the laser writing system used in our work. An optical parametric amplifier system (wavelength: 800 nm; repetition rate: 1 kHz; pulse duration: less than 150 fs.) was employed as the laser-writing source. Then the laser beam was focused on the film surface of the sample by a 40${\times} $ objective with a number aperture (NA) of NA = 0.65 and the focus diameter is evaluated to be 1.5 µm. The As2Se3 film sample was placed on a computer-controlled x–y–z translation stage with a translational accuracy of 0.1 µm. Laser beam power was controlled by an attenuator, and laser irradiation time was controlled with an electronic shutter connected to the computer controller, thus allowing for synchronized laser exposure and stage movement. A CCD camera was subsequently used to observe the processing written into the films. Before the experiment, a proportion of the laser power was measured (1/8) before measuring the bicolor mirror (shown in Fig. 1) under the laser power irradiated to the sample surface. In our work, for convenience of the experiment, laser power was subsequently measured before passing through a bicolor mirror.

 figure: Fig. 1.

Fig. 1. Schematic of the experimental setup for direct laser writing of diffraction gratings in chalcogenide films

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In the experiment, the damage threshold of the prepared film was studied by writing a series of single line waveguide with different power intensity at the optimized writing speed of 1000 µm/s. The diffraction grating was written with the corresponding parameters, while increase the scanning interval to a period of 5µm. Subsequently, in order to accurately calculate the change in refractive index induced by the femtosecond laser with Swanepoel method, a series of large uniform areas (500µm × 500µm) were also written by reducing the line interval to 0.5 µm, while keeping the same laser density with the writing of the gratings.

3.3 Measurement of diffraction efficiency and transmission

Figure 2 shows the setup for recording diffraction efficiency of the prepared gratings. The system mainly consists of a highly stable laser source, integrating spheremeter, and fiber optic spectrometer. CW lasers (808, 980 and 1550 nm) and a SC source were used to obtain diffraction efficiency from visible to near-IR light. The diffracted laser beam was recorded with a fiber optic spectrometer (USB2000+, Ocean optics) supplemented by a powermeter (PowerMax, Coherent). An integrating spheremeter connected to a spectrometer was used to collect the broadband light source, thus remarkably improving measurement reproducibility. The integrating spheremeter aided in suppressing direct hit and reducing the measurement error caused by the shape of light, divergent angle, and responsiveness difference between different positions on the detector. Diffraction properties (diffraction pattern and efficiency) based on different lasers were also investigated thoroughly in the measuring system.

In order to determine the change in refractive index and absorption coefficient of the laser scanning region with Swanepoel method, the transmission spectrum of the film itself and the scanning region was also measured using the same equipment in Fig. 2.

 figure: Fig. 2.

Fig. 2. Schematic of the experimental setup used for recording diffraction efficiency

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4. Measurement results and discussions

4.1 Performance of As2Se3 film

Figure 3(a) and 3(b) depict the optical transmittance spectra and spectral dependence of the refractive index for the As2Se3 films, respectively. The inset in Fig. 3(a) shows the optical band gaps for the As2Se3 film with a value of $\textrm{hv}$ = 1.76 eV. Figure 3(b) shows that the refractive indices of the As2Se3 thin film have reached beyond 2.6 in the IR region, thus benefitting photonic applications. The inset in Fig. 3(b) indicates the Raman spectra of As2Se3 glass targets and films deposited by thermal evaporation. The shapes of the spectra of films were similar to those of the glass targets, and energy dispersive spectroscopy detected the compositions identical to those of the bulk glass targets within an approximate error of measurement of 1 at %. The results indicate the good optical quality of deposited ChG film for photonic devices.

 figure: Fig. 3.

Fig. 3. (a) Transmission curve and (inset) optical band gaps of As2Se3 films; (b) wavelength–refractive index graph and (inset) Raman shift of As2Se3 glass and films.

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4.2 Laser damage threshold of the film

The film prepared by thermal evaporation has high surface quality. After laser irradiation, it was found that the corresponding area will expand, resulting in an increased thickness of the film. Figure 4 depicts the surface profile of the written stripes as a function of laser energy using the surface profiler. The inset in Fig. 4 is the corresponding transmission microscope. It can be seen that higher laser intensity will cause physical damage on the film. The film surface changes from physical damage to refractive index change, when the laser intensity gradually decreased to the value below 38 nJ. It can also be seen from the inset in Fig. 4 that the sharpness of the stripes gradually become blurred as the power decreases.

 figure: Fig. 4.

Fig. 4. Femtosecond laser direct writing surface roughness of a single line, and the inset is a microscope transmission images.

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4.3 Diffraction grating performance and characterization

Diffraction gratings in As2Se3 thin films were first fabricated with different laser energy. The topography of the prepared diffraction gratings was observed using a high-resolution optical microscope (VHX-1000E, Keyence, JAPAN). Figure 5(a) depicts the optical images (80${\times} $) of the prepared gratings in As2Se3 thin film with different laser power irradiations. The sample with increased laser power irradiation exhibited a different color depth. Figure 5(b) presents the magnified views (2000${\times} $) of the gratings, wherein the grating stripes gradually clarified with the increase of pulse energy. When the pulse energy exceeded 38 nJ, the contrast of the stripes significantly increased, and the edges blurred, thus implying film grating changes from refractive index change to physical damage.

 figure: Fig. 5.

Fig. 5. Optical microscopy of the prepared gratings in As2Se3 thin film with different laser power irradiations.(a) 80 times and (b) 2000 times.

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In order to determine whether physical damage occurred when the gratings were written, the surface topography of the irradiation area was further measured using the surface profiler. Figure 6 showed the profile of the grating with the pulse energy of 30 nJ. It was found that the surface profile of the diffraction grating is substantially the same as that the previous written single stripe under 30 nJ laser pulse. The laser-irradiated area exhibits a convex change with a protrusion height of about 20 nm under the pulse energy of 30 nJ.

 figure: Fig. 6.

Fig. 6. Cross section of a grating with laser pulse energy of 30nJ. The inset is a partial enlarged view of the 30nJ grating topography.

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Diffraction efficiency and its variation with wavelength and spectral order are important characteristics of diffraction grating. Therefore, the diffraction pattern and efficiency of the prepared gratings were further characterized. Figure 7 shows the photographs of diffraction patterns recorded from a grating produced at 30 nJ with normal irradiated laser beams. Figures 7(a), 7(b), and 7(c) present the diffraction patterns of a CW laser at λ = 632.8 nm, a SC source with wavelength from 400 nm to 2200 nm, and an 808 nm laser, respectively, thus indicating that the diffraction spot size of 0- and 1-order diffractions is approximately the same, and that diffraction grating exhibits larger diffraction efficiency compared with that at λ = 632.8 nm and 1550 nm. The diffraction patterns of the first two orders were remarkably clear and clean for the CW laser at 632.8 nm and 808 nm. For the SC source, broadband light was diffracted to different angles, leading to colorful light stripes. In this case, the integrating spheremeter added in collecting the broadband light of one diffraction order for spectral measurement.

 figure: Fig. 7.

Fig. 7. Diffraction patterns of recorded from a grating produced at 30nJ. (a) CW laser at λ=632.8 nm, (b) SC source with wavelength from 400 nm to 2200 nm, and (c) an 808 nm laser.

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Figure 8(a) displays the contrast diagrams of diffraction efficiency using a SC source for different writing powers (from 15 nJ to 110 nJ) for grating with a period of 5 µm. Diffraction efficiency first increased as the laser power increased and reached the maximum when the laser power was approximately 30 nJ, thereby indicating a remarkable change in refractive index with the increase in laser energy. Figure 8(b) shows the relationships between diffraction efficiency at 808 nm and the used pulse energy. It can be seen that diffraction efficiency first increased as the laser energy increased and reached the maximum when the laser power was approximately 30 nJ, thereby indicating a remarkable change in refractive index and absorption with the increasing in laser intensity. After then, diffraction efficiency gradually decreased when the laser energy exceeds 38 nJ, due to the state of physical damage of the gratings.

 figure: Fig. 8.

Fig. 8. (a)Contrast diagrams of diffraction efficiency using a SC source and (b) effect of laser power (15nJ–110nJ) on diffraction efficiency at 800nm.

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The diffraction efficiency of the prepared gratings with two monochromatic lasers of 980 nm and 1550 nm in the transparent range was further tested. Figure 9(a) shows the relationships between diffraction efficiency and used laser energy. It can be seen that diffraction efficiency exhibited the same trend with 808 nm laser, but presented a much lower value. Since the absorption of the film can be ignored in the transparent range of above 900 nm, the change of refractive index after laser irradiation can be easily obtained using Eq. (3). As discussed above, when laser pulse energy exceed 30 nJ, the surface of the film will be damaged by the focused laser irradiation, resulting in the grooves in the sample, which means the phase grating began to change into the amplitude grating. Thus, only the refractive index modulation of the phase gratings with the laser power within 15–30 nJ ranges are calculated based on diffraction theory of phase grating, and the results are shown in Fig. 9(b). Table 1 lists the detailed values of the refractive index of As2Se3 films after femtosecond laser irradiation, wherein the use of a laser power at 30 nJ can reach the maximum ${\Delta \textrm{n}}$ = 0.02436 at 1550 nm.

 figure: Fig. 9.

Fig. 9. (a) Contrast diagram of diffraction efficiency using the SC source and CW laser at different wavelengths (980 nm and 1550 nm); (b) effect of laser power (15nJ-30nJ) on refractive index change

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Tables Icon

Table 1. Calculated refractive index modulation under different laser power irradiations

4.4 Diffraction efficiency in absorption region

As shown above, the grating inscribed under laser power of 30 nJ demonstrated a very high diffraction efficiency in the range of 700 to 900 nm. We think this is resulted from the changes of refractive index and absorption in this strong absorption region. Therefore, the refractive index and absorption of the film before and after laser irradiation are further analyzed by the Swanepoel method.

The transmission spectrum of the laser irradiated region (IRR) and unirradiated region (UN-IRR) in the film were carefully measured, as shown Fig. 10(a). Figure 10(b) depicts the refractive index of the IRR and UN-IRR with different wavelengths, the blue curve shows the ${\Delta \textrm{n}}$ of them. It was shown that the refractive index will increase after laser irradiation, and the refractive index change reaches a maximum value when the wavelength is around 800 nm. The maximum refractive index change was estimated to be 0.087 at 808 nm. Figure 9(c) shows the change in absorption coefficient of the IRR and UN-IRR, with the blue curve depicts the change of absorption coefficient (${\Delta \textrm{K}}$). It can be seen that the absorption coefficient of the IRR is always larger than that of the UN-IRR, but the difference between them gradually decreases as the wavelength increases.

 figure: Fig. 10.

Fig. 10. The (a) transmission spectrum, (b) refractive index and (c) absorption coefficient of the IRR (25 nJ) and UN-IRR (0nJ) calculated by Swanepoel method.

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Based on the above calculation and combining with Eq. (2), the diffraction efficiency in the strong absorption region with different wavelengths can be obtained. Figure  11(a) shows the calculated diffraction efficiency of the femtosecond laser irradiation region with a pulse energy of 25 nJ, which is substantially consistent with the diffraction efficiency of the actually measured grating, as shown in Fig. 11(b).

 figure: Fig. 11.

Fig. 11. Evolution of the diffraction efficiency as a function of the wavelength. (a) Calculated by Swanepoel method in combination with Eq. (2) and (b) actual measured.

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5. Conclusions

The current study demonstrated the fabrication of diffraction grating in chalcogenide As2Se3 thin films by femtosecond laser direct writing. The chalcogenide films were prepared by thermal evaporation. Morphologies and optical properties of the films, including refractive index and optical band gaps, were measured and calculated. The laser damage threshold was also estimated by writing a series of single stripes with different laser intensities at an optimized writing speed. Results shown that a transformation process from the refractive index change to physical damage will happen as the irradiated laser energy increased. The grating diffraction results show that the grating with a period of 5 µm inscribed with a laser power of 30 nJ exhibited 1st order diffraction efficiency of 30% at 808 nm. The relationship of the change of refractive index and absorption coefficient of film under different laser irradiation intensity is finally obtained. Maximum refractive index change was estimated to be 0.087 at 808 nm. The large refractive index modulation shows potential in the preparation of photonic devices with complete band gap in chalcogenide films. Also, the relationship of the change of refractive index of As2Se3 film with laser intensity provide important guide for the design and preparation of other photonic devices.

Funding

Natural Science Foundation of Zhejiang Province (LGJ18F050001, LY18F050003, LY19F050003); K. C. Wong Magna Fund in Ningbo University; Open Projects Foundation of Yangtze Optical Fiber and Cable Joint Stock Limited Company (SKLD1801); Department of Education of Zhejiang Province (Y201737033); National Natural Science Foundation of China (61935006).

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21. C. Meneghini and A. Villeneuve, “As2S3 photosensitivity by two-photon absorption: holographic gratings and self-written channel waveguides,” J. Opt. Soc. Am. B 15(12), 2946–2950 (1998). [CrossRef]  

22. C. Florea, J. S. Sanghera, and I. D. Aggarwal, “Direct-write gratings in chalcogenide bulk glasses and fibers using a femtosecond laser,” Opt. Mater. 30(10), 1603–1606 (2008). [CrossRef]  

23. D. G. MacLachlan, R. R. Thomson, C. R. Cunningham, and D. Lee, “Mid-Infrared Volume Phase Gratings Manufactured using Ultrafast Laser Inscription,” Opt. Mater. Express 3(10), 1616–1624 (2013). [CrossRef]  

24. M. S. El-Bana, R. Bohdan, and S. S. Fouad, “Optical characteristics and holographic gratings recording on As30Se70 thin films,” J. Alloys Compd. 686, 115–121 (2016). [CrossRef]  

25. T. Cardinal, O. M. Efimov, L. B. Glebov, K. C. Richardson, and E. V. Stryland, “Waveguide writing in chalcogenide glasses by train of femtosecond laser pulses,” Opt. Mater. 17(3), 379–386 (2001). [CrossRef]  

26. J. Wang, B. He, S. Dai, J. Zhu, and Z. Wei, “Waveguide in Tm3+-Doped Chalcogenide Glass Fabricated by Femtosecond Laser Direct Writing,” IEEE Photonics Technol. Lett. 27(3), 237–240 (2015). [CrossRef]  

27. D. Pudo, E. C. Mägi, and B. J. Eggleton, “Long-period gratings in chalcogenide fibers,” Opt. Express 14(9), 3763–3766 (2006). [CrossRef]  

28. G. Tao, H. Ebendorff-Heidepriem, A. M. Stolyarov, S. Danto, J. V. Badding, Y. Fink, J. Ballato, and A. F. Abouraddy, “Infrared fibers,” Adv. Opt. Photonics 7(2), 379 (2015). [CrossRef]  

29. L. Zhu, D. Yang, L. Wang, J. Zeng, Q. Zhang, M. Xiea, S. Zhang, P. Zhang, and S. Dai, “Optical and thermal stability of Ge-As-Se chalcogenide glasses for femtosecond laser writing,” Opt.Matter 85, 220–225 (2018). [CrossRef]  

30. T. G. Robinson, R. G. Decorby, J. N. Mcmullin, C. J. Haugen, S. O. Kasap, and T. Dancho, “Strong Bragg gratings photoinduced by 633-nm illumination in evaporated As2Se3 thin films,” Opt. Lett. 28(6), 459–461 (2003). [CrossRef]  

31. Y. Jin, B. Song, Z. Jia, Y. Zhang, C. Lin, X. Wang, and S. Dai, “Improvement of Swanepoel method for deriving the thickness and the optical properties of chalcogenide thin films,” Opt. Express 25(1), 440–451 (2017). [CrossRef]  

32. Y. Jin, B. Song, C. Lin, P. Zhang, S. Dai, T. Xu, and Q. Nie, “Extension of the Swanepoel method for obtaining the refractive index of chalcogenide thin films accurately at an arbitrary wavenumber,” Opt. Express 25(25), 31273–31280 (2017). [CrossRef]  

33. Y. Ohmachi and T. Igo, “Laser-Induced Refractive-Index Change in As–S–Ge Glasses,” Appl. Phys. Lett. 20(12), 506–508 (1972). [CrossRef]  

34. A. B. Seddon, “Chalcogenide glasses: A review of their preparation, properties and applications,” J. Non-Cryst. Solids 184, 44–50 (1995). [CrossRef]  

35. M. Mishra, R. Chauhan, A. Katiyar, and K. K. Srivastava, “Optical properties of amorphous thin film of Se-Te-Ag system prepared by using thermal evaporation technique,” Prog. Nat. Sci. 21(1), 36–39 (2011). [CrossRef]  

References

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  1. A. Zakery and S. R. Elliott, “Optical properties and applications of chalcogenide glasses: a review,” J. Non-Cryst. Solids 330(1-3), 1–12 (2003).
    [Crossref]
  2. C. Quémard, F. Smektala, V. Couderc, A. Barthélémy, and J. Lucas, “Chalcogenide glasses with high non linear optical properties for telecommunications,” J. Phys. Chem. Solids 62(8), 1435–1440 (2001).
    [Crossref]
  3. J. S. Sanghera, C. M. Florea, L. B. Shaw, P. Pureza, V. Q. Nguyen, M. Bashkansky, Z. Dutton, and I. D. Aggarwal, “Non-linear properties of chalcogenide glasses and fibers,” J. Non-Cryst. Solids 354(2-9), 462–467 (2008).
    [Crossref]
  4. H. Lin, Y. Song, Y. Huang, D. Kita, S. Deckoff-Jones, K. Wang, L. Li, J. Li, H. Zheng, Z. Luo, H. Wang, S. Novak, A. Yadav, C. Huang, R. Shiue, D. Englund, T. Gu, D. Hewak, K. Richardson, J. Kong, and J. Hu, “Chalcogenide Glass-on-Graphene Photonics,” Nat. Photonics 11(12), 798–805 (2017).
    [Crossref]
  5. Y. Xu, H. Guo, X. Xiao, P. Wang, X. Cui, M. Lu, C. Lin, S. Dai, and B. Peng, “High Verdet constants and diamagnetic responses of GeS2-In2S3-PbI2 chalcogenide glasses for integrated optics applications,” Opt. Express 25(17), 20410 (2017).
    [Crossref]
  6. A. F. Abouraddy, G. Tao, J. J. Kaufman, and S. Shabahang, “Dispersion characterization of chalcogenide bulk glass, composite fibers, and robust nanotapers,” J. Opt. Soc. Am. B 30(9), 2498–2506 (2013).
    [Crossref]
  7. K. Suzuki, Y. Hamachi, and T. Baba, “Fabrication and characterization of chalcogenide glass photonic crystal waveguides,” Opt. Express 17(25), 22393–22400 (2009).
    [Crossref]
  8. Q. Du, Z. Luo, H. Zhong, Y. Zhang, Y. Huang, T. Du, W. Zhang, T. Gu, and J. Hu, “Chip-scale broadband spectroscopic chemical sensing using an integrated supercontinuum source in a chalcogenide glass waveguide,” Photonics Res. 6(6), 506–510 (2018).
    [Crossref]
  9. D. Maystre, “Diffraction gratings: An amazing phenomenon,” C. R. Phys. 14(4), 381–392 (2013).
    [Crossref]
  10. X. Wang, X. Liu, and X. Wang, “Hydrogel diffraction grating as sensor: A tool for studying volume phase transition of thermo-responsive hydrogel,” Sens. Actuators, B 204, 611–616 (2014).
    [Crossref]
  11. E. G. Loewen and E. Popov, “Diffraction gratings and applications,” Lasers Optics & Photonics (2012).
  12. C. Graulig, R. Riesenberg, and A. Grjasnow, “Imaging and dispersion analysis of a diffractive optical element for infrared sensors,” Optik (Munich, Ger.) 124(14), 1777–1782 (2013).
    [Crossref]
  13. G. S. Spagnolo and D. Ambrosini, “Diffractive optical element based sensor for roughness measurement,” Sens. Actuators, A 100(2-3), 180–186 (2002).
    [Crossref]
  14. Q. Tan, Q. He, Y. Yan, G. Jin, and D. Xu, “Spatial-frequency spectrum analysis of the performance of diffractive optical element for beam smoothing,” Optik (Munich, Ger.) 113(4), 163–166 (2002).
    [Crossref]
  15. D. Freeman, S. Madden, and B. Luther-Davies, “Fabrication of planar photonic crystals in a chalcogenide glass using a focused ion beam,” Opt. Express 13(8), 3079–3086 (2005).
    [Crossref]
  16. P. Zhang, Z. Zhao, J. Zeng, Q. Zhang, X. Wang, F. Chen, X. Shen, and S. Dai, “Fabrication and characterization of Ge20As20Se15Te45 chalcogenide glass for photonic crystal by nanoimprint lithography,” Opt. Mater. Express 6(6), 1853–1860 (2016).
    [Crossref]
  17. D. Paipulas, V. Kudriašov, M. Malinauskas, V. Smilgevičius, and V. Sirutkaitis, “Diffraction grating fabrication in lithium niobate and KDP crystals with femtosecond laser pulses,” Appl. Phys. A 104(3), 769–773 (2011).
    [Crossref]
  18. D. Dai, J. J. He, and S. He, “Elimination of multimode effects in a silicon-on-insulator etched diffraction grating demultiplexer with bi-level taper structure,” IEEE J. Sel. Top. Quantum Electron. 11(2), 439–443 (2005).
    [Crossref]
  19. S. Wong, M. Deubel, F. Pérez-Willard, S. John, G. A. Ozin, M. Wegener, and G. von Freymann, “Direct Laser Writing of Three- Dimensional Photonic Crystals with a Complete Photonic Bandgap in Chalcogenide Glasses,” Adv. Mater. 18(3), 265–269 (2006).
    [Crossref]
  20. M. Beresna and P. G. Kazansky, “Polarization diffraction grating produced by femtosecond laser nanostructuring in glass,” Opt. Lett. 35(10), 1662–1664 (2010).
    [Crossref]
  21. C. Meneghini and A. Villeneuve, “As2S3 photosensitivity by two-photon absorption: holographic gratings and self-written channel waveguides,” J. Opt. Soc. Am. B 15(12), 2946–2950 (1998).
    [Crossref]
  22. C. Florea, J. S. Sanghera, and I. D. Aggarwal, “Direct-write gratings in chalcogenide bulk glasses and fibers using a femtosecond laser,” Opt. Mater. 30(10), 1603–1606 (2008).
    [Crossref]
  23. D. G. MacLachlan, R. R. Thomson, C. R. Cunningham, and D. Lee, “Mid-Infrared Volume Phase Gratings Manufactured using Ultrafast Laser Inscription,” Opt. Mater. Express 3(10), 1616–1624 (2013).
    [Crossref]
  24. M. S. El-Bana, R. Bohdan, and S. S. Fouad, “Optical characteristics and holographic gratings recording on As30Se70 thin films,” J. Alloys Compd. 686, 115–121 (2016).
    [Crossref]
  25. T. Cardinal, O. M. Efimov, L. B. Glebov, K. C. Richardson, and E. V. Stryland, “Waveguide writing in chalcogenide glasses by train of femtosecond laser pulses,” Opt. Mater. 17(3), 379–386 (2001).
    [Crossref]
  26. J. Wang, B. He, S. Dai, J. Zhu, and Z. Wei, “Waveguide in Tm3+-Doped Chalcogenide Glass Fabricated by Femtosecond Laser Direct Writing,” IEEE Photonics Technol. Lett. 27(3), 237–240 (2015).
    [Crossref]
  27. D. Pudo, E. C. Mägi, and B. J. Eggleton, “Long-period gratings in chalcogenide fibers,” Opt. Express 14(9), 3763–3766 (2006).
    [Crossref]
  28. G. Tao, H. Ebendorff-Heidepriem, A. M. Stolyarov, S. Danto, J. V. Badding, Y. Fink, J. Ballato, and A. F. Abouraddy, “Infrared fibers,” Adv. Opt. Photonics 7(2), 379 (2015).
    [Crossref]
  29. L. Zhu, D. Yang, L. Wang, J. Zeng, Q. Zhang, M. Xiea, S. Zhang, P. Zhang, and S. Dai, “Optical and thermal stability of Ge-As-Se chalcogenide glasses for femtosecond laser writing,” Opt.Matter 85, 220–225 (2018).
    [Crossref]
  30. T. G. Robinson, R. G. Decorby, J. N. Mcmullin, C. J. Haugen, S. O. Kasap, and T. Dancho, “Strong Bragg gratings photoinduced by 633-nm illumination in evaporated As2Se3 thin films,” Opt. Lett. 28(6), 459–461 (2003).
    [Crossref]
  31. Y. Jin, B. Song, Z. Jia, Y. Zhang, C. Lin, X. Wang, and S. Dai, “Improvement of Swanepoel method for deriving the thickness and the optical properties of chalcogenide thin films,” Opt. Express 25(1), 440–451 (2017).
    [Crossref]
  32. Y. Jin, B. Song, C. Lin, P. Zhang, S. Dai, T. Xu, and Q. Nie, “Extension of the Swanepoel method for obtaining the refractive index of chalcogenide thin films accurately at an arbitrary wavenumber,” Opt. Express 25(25), 31273–31280 (2017).
    [Crossref]
  33. Y. Ohmachi and T. Igo, “Laser-Induced Refractive-Index Change in As–S–Ge Glasses,” Appl. Phys. Lett. 20(12), 506–508 (1972).
    [Crossref]
  34. A. B. Seddon, “Chalcogenide glasses: A review of their preparation, properties and applications,” J. Non-Cryst. Solids 184, 44–50 (1995).
    [Crossref]
  35. M. Mishra, R. Chauhan, A. Katiyar, and K. K. Srivastava, “Optical properties of amorphous thin film of Se-Te-Ag system prepared by using thermal evaporation technique,” Prog. Nat. Sci. 21(1), 36–39 (2011).
    [Crossref]

2018 (2)

Q. Du, Z. Luo, H. Zhong, Y. Zhang, Y. Huang, T. Du, W. Zhang, T. Gu, and J. Hu, “Chip-scale broadband spectroscopic chemical sensing using an integrated supercontinuum source in a chalcogenide glass waveguide,” Photonics Res. 6(6), 506–510 (2018).
[Crossref]

L. Zhu, D. Yang, L. Wang, J. Zeng, Q. Zhang, M. Xiea, S. Zhang, P. Zhang, and S. Dai, “Optical and thermal stability of Ge-As-Se chalcogenide glasses for femtosecond laser writing,” Opt.Matter 85, 220–225 (2018).
[Crossref]

2017 (4)

2016 (2)

2015 (2)

J. Wang, B. He, S. Dai, J. Zhu, and Z. Wei, “Waveguide in Tm3+-Doped Chalcogenide Glass Fabricated by Femtosecond Laser Direct Writing,” IEEE Photonics Technol. Lett. 27(3), 237–240 (2015).
[Crossref]

G. Tao, H. Ebendorff-Heidepriem, A. M. Stolyarov, S. Danto, J. V. Badding, Y. Fink, J. Ballato, and A. F. Abouraddy, “Infrared fibers,” Adv. Opt. Photonics 7(2), 379 (2015).
[Crossref]

2014 (1)

X. Wang, X. Liu, and X. Wang, “Hydrogel diffraction grating as sensor: A tool for studying volume phase transition of thermo-responsive hydrogel,” Sens. Actuators, B 204, 611–616 (2014).
[Crossref]

2013 (4)

2011 (2)

M. Mishra, R. Chauhan, A. Katiyar, and K. K. Srivastava, “Optical properties of amorphous thin film of Se-Te-Ag system prepared by using thermal evaporation technique,” Prog. Nat. Sci. 21(1), 36–39 (2011).
[Crossref]

D. Paipulas, V. Kudriašov, M. Malinauskas, V. Smilgevičius, and V. Sirutkaitis, “Diffraction grating fabrication in lithium niobate and KDP crystals with femtosecond laser pulses,” Appl. Phys. A 104(3), 769–773 (2011).
[Crossref]

2010 (1)

2009 (1)

2008 (2)

J. S. Sanghera, C. M. Florea, L. B. Shaw, P. Pureza, V. Q. Nguyen, M. Bashkansky, Z. Dutton, and I. D. Aggarwal, “Non-linear properties of chalcogenide glasses and fibers,” J. Non-Cryst. Solids 354(2-9), 462–467 (2008).
[Crossref]

C. Florea, J. S. Sanghera, and I. D. Aggarwal, “Direct-write gratings in chalcogenide bulk glasses and fibers using a femtosecond laser,” Opt. Mater. 30(10), 1603–1606 (2008).
[Crossref]

2006 (2)

S. Wong, M. Deubel, F. Pérez-Willard, S. John, G. A. Ozin, M. Wegener, and G. von Freymann, “Direct Laser Writing of Three- Dimensional Photonic Crystals with a Complete Photonic Bandgap in Chalcogenide Glasses,” Adv. Mater. 18(3), 265–269 (2006).
[Crossref]

D. Pudo, E. C. Mägi, and B. J. Eggleton, “Long-period gratings in chalcogenide fibers,” Opt. Express 14(9), 3763–3766 (2006).
[Crossref]

2005 (2)

D. Freeman, S. Madden, and B. Luther-Davies, “Fabrication of planar photonic crystals in a chalcogenide glass using a focused ion beam,” Opt. Express 13(8), 3079–3086 (2005).
[Crossref]

D. Dai, J. J. He, and S. He, “Elimination of multimode effects in a silicon-on-insulator etched diffraction grating demultiplexer with bi-level taper structure,” IEEE J. Sel. Top. Quantum Electron. 11(2), 439–443 (2005).
[Crossref]

2003 (2)

2002 (2)

G. S. Spagnolo and D. Ambrosini, “Diffractive optical element based sensor for roughness measurement,” Sens. Actuators, A 100(2-3), 180–186 (2002).
[Crossref]

Q. Tan, Q. He, Y. Yan, G. Jin, and D. Xu, “Spatial-frequency spectrum analysis of the performance of diffractive optical element for beam smoothing,” Optik (Munich, Ger.) 113(4), 163–166 (2002).
[Crossref]

2001 (2)

C. Quémard, F. Smektala, V. Couderc, A. Barthélémy, and J. Lucas, “Chalcogenide glasses with high non linear optical properties for telecommunications,” J. Phys. Chem. Solids 62(8), 1435–1440 (2001).
[Crossref]

T. Cardinal, O. M. Efimov, L. B. Glebov, K. C. Richardson, and E. V. Stryland, “Waveguide writing in chalcogenide glasses by train of femtosecond laser pulses,” Opt. Mater. 17(3), 379–386 (2001).
[Crossref]

1998 (1)

1995 (1)

A. B. Seddon, “Chalcogenide glasses: A review of their preparation, properties and applications,” J. Non-Cryst. Solids 184, 44–50 (1995).
[Crossref]

1972 (1)

Y. Ohmachi and T. Igo, “Laser-Induced Refractive-Index Change in As–S–Ge Glasses,” Appl. Phys. Lett. 20(12), 506–508 (1972).
[Crossref]

Abouraddy, A. F.

G. Tao, H. Ebendorff-Heidepriem, A. M. Stolyarov, S. Danto, J. V. Badding, Y. Fink, J. Ballato, and A. F. Abouraddy, “Infrared fibers,” Adv. Opt. Photonics 7(2), 379 (2015).
[Crossref]

A. F. Abouraddy, G. Tao, J. J. Kaufman, and S. Shabahang, “Dispersion characterization of chalcogenide bulk glass, composite fibers, and robust nanotapers,” J. Opt. Soc. Am. B 30(9), 2498–2506 (2013).
[Crossref]

Aggarwal, I. D.

J. S. Sanghera, C. M. Florea, L. B. Shaw, P. Pureza, V. Q. Nguyen, M. Bashkansky, Z. Dutton, and I. D. Aggarwal, “Non-linear properties of chalcogenide glasses and fibers,” J. Non-Cryst. Solids 354(2-9), 462–467 (2008).
[Crossref]

C. Florea, J. S. Sanghera, and I. D. Aggarwal, “Direct-write gratings in chalcogenide bulk glasses and fibers using a femtosecond laser,” Opt. Mater. 30(10), 1603–1606 (2008).
[Crossref]

Ambrosini, D.

G. S. Spagnolo and D. Ambrosini, “Diffractive optical element based sensor for roughness measurement,” Sens. Actuators, A 100(2-3), 180–186 (2002).
[Crossref]

Baba, T.

Badding, J. V.

G. Tao, H. Ebendorff-Heidepriem, A. M. Stolyarov, S. Danto, J. V. Badding, Y. Fink, J. Ballato, and A. F. Abouraddy, “Infrared fibers,” Adv. Opt. Photonics 7(2), 379 (2015).
[Crossref]

Ballato, J.

G. Tao, H. Ebendorff-Heidepriem, A. M. Stolyarov, S. Danto, J. V. Badding, Y. Fink, J. Ballato, and A. F. Abouraddy, “Infrared fibers,” Adv. Opt. Photonics 7(2), 379 (2015).
[Crossref]

Barthélémy, A.

C. Quémard, F. Smektala, V. Couderc, A. Barthélémy, and J. Lucas, “Chalcogenide glasses with high non linear optical properties for telecommunications,” J. Phys. Chem. Solids 62(8), 1435–1440 (2001).
[Crossref]

Bashkansky, M.

J. S. Sanghera, C. M. Florea, L. B. Shaw, P. Pureza, V. Q. Nguyen, M. Bashkansky, Z. Dutton, and I. D. Aggarwal, “Non-linear properties of chalcogenide glasses and fibers,” J. Non-Cryst. Solids 354(2-9), 462–467 (2008).
[Crossref]

Beresna, M.

Bohdan, R.

M. S. El-Bana, R. Bohdan, and S. S. Fouad, “Optical characteristics and holographic gratings recording on As30Se70 thin films,” J. Alloys Compd. 686, 115–121 (2016).
[Crossref]

Cardinal, T.

T. Cardinal, O. M. Efimov, L. B. Glebov, K. C. Richardson, and E. V. Stryland, “Waveguide writing in chalcogenide glasses by train of femtosecond laser pulses,” Opt. Mater. 17(3), 379–386 (2001).
[Crossref]

Chauhan, R.

M. Mishra, R. Chauhan, A. Katiyar, and K. K. Srivastava, “Optical properties of amorphous thin film of Se-Te-Ag system prepared by using thermal evaporation technique,” Prog. Nat. Sci. 21(1), 36–39 (2011).
[Crossref]

Chen, F.

Couderc, V.

C. Quémard, F. Smektala, V. Couderc, A. Barthélémy, and J. Lucas, “Chalcogenide glasses with high non linear optical properties for telecommunications,” J. Phys. Chem. Solids 62(8), 1435–1440 (2001).
[Crossref]

Cui, X.

Cunningham, C. R.

Dai, D.

D. Dai, J. J. He, and S. He, “Elimination of multimode effects in a silicon-on-insulator etched diffraction grating demultiplexer with bi-level taper structure,” IEEE J. Sel. Top. Quantum Electron. 11(2), 439–443 (2005).
[Crossref]

Dai, S.

Dancho, T.

Danto, S.

G. Tao, H. Ebendorff-Heidepriem, A. M. Stolyarov, S. Danto, J. V. Badding, Y. Fink, J. Ballato, and A. F. Abouraddy, “Infrared fibers,” Adv. Opt. Photonics 7(2), 379 (2015).
[Crossref]

Deckoff-Jones, S.

H. Lin, Y. Song, Y. Huang, D. Kita, S. Deckoff-Jones, K. Wang, L. Li, J. Li, H. Zheng, Z. Luo, H. Wang, S. Novak, A. Yadav, C. Huang, R. Shiue, D. Englund, T. Gu, D. Hewak, K. Richardson, J. Kong, and J. Hu, “Chalcogenide Glass-on-Graphene Photonics,” Nat. Photonics 11(12), 798–805 (2017).
[Crossref]

Decorby, R. G.

Deubel, M.

S. Wong, M. Deubel, F. Pérez-Willard, S. John, G. A. Ozin, M. Wegener, and G. von Freymann, “Direct Laser Writing of Three- Dimensional Photonic Crystals with a Complete Photonic Bandgap in Chalcogenide Glasses,” Adv. Mater. 18(3), 265–269 (2006).
[Crossref]

Du, Q.

Q. Du, Z. Luo, H. Zhong, Y. Zhang, Y. Huang, T. Du, W. Zhang, T. Gu, and J. Hu, “Chip-scale broadband spectroscopic chemical sensing using an integrated supercontinuum source in a chalcogenide glass waveguide,” Photonics Res. 6(6), 506–510 (2018).
[Crossref]

Du, T.

Q. Du, Z. Luo, H. Zhong, Y. Zhang, Y. Huang, T. Du, W. Zhang, T. Gu, and J. Hu, “Chip-scale broadband spectroscopic chemical sensing using an integrated supercontinuum source in a chalcogenide glass waveguide,” Photonics Res. 6(6), 506–510 (2018).
[Crossref]

Dutton, Z.

J. S. Sanghera, C. M. Florea, L. B. Shaw, P. Pureza, V. Q. Nguyen, M. Bashkansky, Z. Dutton, and I. D. Aggarwal, “Non-linear properties of chalcogenide glasses and fibers,” J. Non-Cryst. Solids 354(2-9), 462–467 (2008).
[Crossref]

Ebendorff-Heidepriem, H.

G. Tao, H. Ebendorff-Heidepriem, A. M. Stolyarov, S. Danto, J. V. Badding, Y. Fink, J. Ballato, and A. F. Abouraddy, “Infrared fibers,” Adv. Opt. Photonics 7(2), 379 (2015).
[Crossref]

Efimov, O. M.

T. Cardinal, O. M. Efimov, L. B. Glebov, K. C. Richardson, and E. V. Stryland, “Waveguide writing in chalcogenide glasses by train of femtosecond laser pulses,” Opt. Mater. 17(3), 379–386 (2001).
[Crossref]

Eggleton, B. J.

El-Bana, M. S.

M. S. El-Bana, R. Bohdan, and S. S. Fouad, “Optical characteristics and holographic gratings recording on As30Se70 thin films,” J. Alloys Compd. 686, 115–121 (2016).
[Crossref]

Elliott, S. R.

A. Zakery and S. R. Elliott, “Optical properties and applications of chalcogenide glasses: a review,” J. Non-Cryst. Solids 330(1-3), 1–12 (2003).
[Crossref]

Englund, D.

H. Lin, Y. Song, Y. Huang, D. Kita, S. Deckoff-Jones, K. Wang, L. Li, J. Li, H. Zheng, Z. Luo, H. Wang, S. Novak, A. Yadav, C. Huang, R. Shiue, D. Englund, T. Gu, D. Hewak, K. Richardson, J. Kong, and J. Hu, “Chalcogenide Glass-on-Graphene Photonics,” Nat. Photonics 11(12), 798–805 (2017).
[Crossref]

Fink, Y.

G. Tao, H. Ebendorff-Heidepriem, A. M. Stolyarov, S. Danto, J. V. Badding, Y. Fink, J. Ballato, and A. F. Abouraddy, “Infrared fibers,” Adv. Opt. Photonics 7(2), 379 (2015).
[Crossref]

Florea, C.

C. Florea, J. S. Sanghera, and I. D. Aggarwal, “Direct-write gratings in chalcogenide bulk glasses and fibers using a femtosecond laser,” Opt. Mater. 30(10), 1603–1606 (2008).
[Crossref]

Florea, C. M.

J. S. Sanghera, C. M. Florea, L. B. Shaw, P. Pureza, V. Q. Nguyen, M. Bashkansky, Z. Dutton, and I. D. Aggarwal, “Non-linear properties of chalcogenide glasses and fibers,” J. Non-Cryst. Solids 354(2-9), 462–467 (2008).
[Crossref]

Fouad, S. S.

M. S. El-Bana, R. Bohdan, and S. S. Fouad, “Optical characteristics and holographic gratings recording on As30Se70 thin films,” J. Alloys Compd. 686, 115–121 (2016).
[Crossref]

Freeman, D.

Glebov, L. B.

T. Cardinal, O. M. Efimov, L. B. Glebov, K. C. Richardson, and E. V. Stryland, “Waveguide writing in chalcogenide glasses by train of femtosecond laser pulses,” Opt. Mater. 17(3), 379–386 (2001).
[Crossref]

Graulig, C.

C. Graulig, R. Riesenberg, and A. Grjasnow, “Imaging and dispersion analysis of a diffractive optical element for infrared sensors,” Optik (Munich, Ger.) 124(14), 1777–1782 (2013).
[Crossref]

Grjasnow, A.

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Figures (11)

Fig. 1.
Fig. 1. Schematic of the experimental setup for direct laser writing of diffraction gratings in chalcogenide films
Fig. 2.
Fig. 2. Schematic of the experimental setup used for recording diffraction efficiency
Fig. 3.
Fig. 3. (a) Transmission curve and (inset) optical band gaps of As2Se3 films; (b) wavelength–refractive index graph and (inset) Raman shift of As2Se3 glass and films.
Fig. 4.
Fig. 4. Femtosecond laser direct writing surface roughness of a single line, and the inset is a microscope transmission images.
Fig. 5.
Fig. 5. Optical microscopy of the prepared gratings in As2Se3 thin film with different laser power irradiations.(a) 80 times and (b) 2000 times.
Fig. 6.
Fig. 6. Cross section of a grating with laser pulse energy of 30nJ. The inset is a partial enlarged view of the 30nJ grating topography.
Fig. 7.
Fig. 7. Diffraction patterns of recorded from a grating produced at 30nJ. (a) CW laser at λ=632.8 nm, (b) SC source with wavelength from 400 nm to 2200 nm, and (c) an 808 nm laser.
Fig. 8.
Fig. 8. (a)Contrast diagrams of diffraction efficiency using a SC source and (b) effect of laser power (15nJ–110nJ) on diffraction efficiency at 800nm.
Fig. 9.
Fig. 9. (a) Contrast diagram of diffraction efficiency using the SC source and CW laser at different wavelengths (980 nm and 1550 nm); (b) effect of laser power (15nJ-30nJ) on refractive index change
Fig. 10.
Fig. 10. The (a) transmission spectrum, (b) refractive index and (c) absorption coefficient of the IRR (25 nJ) and UN-IRR (0nJ) calculated by Swanepoel method.
Fig. 11.
Fig. 11. Evolution of the diffraction efficiency as a function of the wavelength. (a) Calculated by Swanepoel method in combination with Eq. (2) and (b) actual measured.

Tables (1)

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Table 1. Calculated refractive index modulation under different laser power irradiations

Equations (7)

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I 0 I i = exp ( KH cos α ) [ co s 2 ( π Δ nH λ cos α ) + cos h 2 ( Δ KH 4 cos α ) 1 ] I 1 I i = exp ( KH cos α ) [ si n 2 ( π Δ nH λ cos α ) + sin h 2 ( Δ KH 4 cos α ) ]
η = I 1 I 0 = si n 2 ( π Δ nH λ cos α ) + sin h 2 ( Δ KH 4 cos α ) co s 2 ( π Δ nH λ cos α ) + cos h 2 ( Δ KH 4 cos α ) 1
η = I 1 I 0 = si n 2 ( π Δ nH λ cos α ) co s 2 ( π Δ nH λ cos α ) = ta n 2 ( π Δ nH λ cos α )
Δ n = λ cos α arctan ( η ) π H
n = 2 s T M T m T M T m + ( 2 s T M T m T M T m + s 2 + 1 2 ) 2 s 2
x = 8 n 2 s T M + ( n 2 1 ) ( n 2 s 2 ) { [ 8 n 2 s T M + ( n 2 1 ) ( n 2 s 2 ) ] 2 ( n 2 1 ) 3 ( n 2 s 4 ) } ( n 1 ) 3 ( n s 2 )
α = l n x d 2 ¯

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