Towards a Highly Sensitive Pressure Sensor Using an Infrared (IR) Laser and a Two-dimensional (2-D) Photonic Crystal Waveguide
C.S. Mishra, S. Das, M.R. Naya, P.D. Pukhrambam, A. Panda and G. Palai
We propose a detailed analysis of a novel two-dimensional (2-D) photonic crystal (PhC) structure to envisage a highly sensitive pressure sensor in the infrared (IR) wavelength range by using an IR laser source. The sensing performances are evaluated by separately designing the proposed structure on InAs and ZnO substrate. The sensor configuration is realized with the arrangement of circular air holes in the triangular lattice configuration having a central line defect. The mainstay of the present research is to study the variation in photonic band gap (PBG) using plane wave expansion (PWE) technique with respect to change in pressure from 1 to 5 GPa across the structure. In addition to this, the transmission spectrum is investigated for different applied pressures in both the InAs and ZnO-based structures. Vital sensing performance like sensitivity and quality factors are computed by analysing the shifting nature of the resonant mode wavelength in the transmission spectrum. We observed a remarkable sensitivity of 75 and 40 nm/ GPa for the proposed InAs-based and ZnO-based PhC sensor, respectively. Also, the effect of different normalized air hole radius is thoroughly studied on the variation in the band gap size. A comparative analysis of the sensor outcomes with respect to the previously published works is presented to prove the superiority of the present research.
Keywords: Infrared (IR) laser, two-dimensional (2-D) photonic crystal waveguide, pressure sensor, photonic band gap (PBG), transmission spectrum