Abstract

In this article, we propose two laser-controlled Fano resonance refractive index (RI) sensors based on eccentric hole fibers (EHFs) integrated with photo-sensitive azobenzene (azo) by exploiting whispering gallery mode (WGM) coupling between the eccentric hole and the EHF microresonators. Azo coating is coated over the external surface of the EHFs to achieve laser tuning of the RI sensing range. Fano resonance would emerge when the phase matching condition of the WGMs that respectively propagate through the azo coating and the eccentric hole is satisfied. Fano resonance sensing with tunable RI range by adjusting the laser power density is theoretically demonstrated. The EHF-based Fano resonance sensor having the silica-based eccentric hole infiltrated with liquid sample of RI between 1.61364 and 1.61436 achieves a RI sensitivity of 875.185 nm/RIU, while the RI sensitivity of the one with a higher index layer serving as the internal surface of the eccentric hole turns to be 1106.351 nm/RIU for a RI range of 1.33748 to 1.33805. More significantly, simulation results indicate that as 5 mW/mm² laser is applied, the RI sensing ranges of the proposed Fano resonance sensors respectively show 101.39% and 101.75% increases compared with the cases when no laser illumination is applied. The EHF-based Fano resonance sensors provide promising candidates for applications in bio/chemical sensing with laser-controlled extended RI sensing range. And moreover, the proposed laser tuning method paves a new way toward developing tunable photonic devices and all-optical networking systems with desired operation wavelength ranges.

Microstructured optical fiber for multichannel sensing based on Fano resonance of the whispering gallery modes

Wei Lin, Hao Zhang, Shih-Chi Chen, Bo Liu, and Yan-Ge Liu
Opt. Express 25(2) 994-1004 (2017)

Surface plasmon resonance sensor based on eccentric core photonic quasi-crystal fiber with indium tin oxide

Qiang Liu, Jiudi Sun, Yudan Sun, Wei Liu, Famei Wang, Lin Yang, Chao Liu, Qingyu Liu, Qian Li, Zonghuan Ren, Tao Sun, and Paul K. Chu
Appl. Opt. 58(25) 6848-6853 (2019)

Multiple Fano resonance refractive index sensor based on a plasmonic metal-insulator-metal based Taiji resonator

Huibo Fan, Hongwei Fan, and Huili Fan
J. Opt. Soc. Am. B 39(1) 32-39 (2022)

Thermo-optic tuning of a nematic liquid crystal-filled capillary whispering gallery mode resonator

Zhe Wang, Arun Kumar Mallik, Fangfang Wei, Zhuochen Wang, Anuradha Rout, Qiang Wu, and Yuliya Semenova
Opt. Express 29(15) 23569-23581 (2021)

Investigation of refractive index sensing based on Fano resonance in fiber Bragg grating ring resonators

Carlo Edoardo Campanella, Francesco De Leonardis, Lorenzo Mastronardi, Pietro Malara, Gianluca Gagliardi, and Vittorio M. N. Passaro
Opt. Express 23(11) 14301-14313 (2015)