scholarly journals High-Sensitive TM Modes in Photonic Crystal Nanobeam Cavity with Horizontal Air Gap for Refractive Index Sensing

2019 ◽  
Vol 9 (5) ◽  
pp. 967 ◽  
Author(s):  
Jin-Kyu Yang ◽  
Chae-Young Kim ◽  
Minji Lee
Keyword(s):  
Refractive Index ◽  
Photonic Crystal ◽  
Refractive Index Change ◽  
Air Gap ◽  
Q Factor ◽  
Practical Applications ◽  
Refractive Index Sensing ◽  
Tm Mode ◽  
Cavity Structure ◽  
New Type

We propose a new type of refractive index sensing based on the transverse magnetic (TM) modes in the photonic crystal (PhC) nanobeam (NB) cavity with a horizontal air gap. The electric field of the resonant TM mode is strongly confined within the horizontal air gap present at the PhC NB cavity. In order to increase the quality (Q) factor and the sensitivity (S) of the refractive index change in the air simultaneously, the cavity structure is fully optimized. Because of the trade-off between the Q-factor and S of the TM mode in the PhC NB cavity with an air gap, there is an optimal thickness of the air gap in the dielectric slot. From the numerical simulation results, S can exceed 1000 nm/RIU with Q > 40,000. When the dielectric slot becomes thin, S could be higher than 1200 nm/RIU. For practical applications, we suggest an Si-based PhC NB cavity with a horizontal SiO2 slot structure which can also provide high S with a high Q-factor after a very fine selective wet etching process. This new type of TM resonant mode in the PhC NB cavity can be an ideal platform for compact sensors in photonic integrated circuits for TM waveguide systems.

scholarly journals Phenomenon of Electromagnetic Field Resonance in Metal and Dielectric Gratings and Its Possible Practical Applications

2020 ◽  
Vol 5 (3) ◽  
pp. 49
Author(s):  
Stefano Bellucci ◽  
Andrii Bendziak ◽  
Oleksandr Vernyhor ◽  
Volodymyr M. Fitio
Keyword(s):  
Refractive Index ◽  
Buffer Layer ◽  
Propagation Constant ◽  
Refractive Index Change ◽  
Dielectric Substrate ◽  
Angular Sensitivity ◽  
Practical Applications ◽  
Dielectric Gratings ◽  
Constant Change ◽  
Dielectric Grating

Calculations of the field distribution in the structure of the dielectric substrate/buffer layer/volume phase grating/analyzed medium were performed. It is shown that in the presence of a buffer layer with a low refractive index in the dielectric waveguide leads to a shift of the maximum field at the waveguide resonance into analyzed medium. As a result, the spectral and angular sensitivity of the corresponding sensor increases. Based on the waveguide equation, analytical expressions are obtained that connect the spectral and angular sensitivity of the sensor to the sensitivity of the propagation constant change due to the refractive index change of the analyzed medium. The conditions for the excitation of the resonance of surface plasmon–polariton waves in the structure with a metal or dielectric grating on a metal substrate are also given. The fields that occur at resonance for silver and gold gratings are calculated.

Photonic crystal fiber based modal interferometer for refractive index sensing

2014 ◽  
Author(s):  
Ming Deng ◽  
Xiaokang Sun ◽  
Wei Huang ◽  
Huifeng Wei ◽  
Jiang Li
Keyword(s):  
Refractive Index ◽  
Photonic Crystal ◽  
Photonic Crystal Fiber ◽  
Crystal Fiber ◽  
Refractive Index Sensing
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