1-Dimensional silicon photonic crystal pressure sensor for the measurement of low pressure

Abstract

In this article we proposed a one-dimensional (1D) silicon photonic-crystal (PC) as a highly sensitive pressure sensor to measure the applied hydrostatic pressure. A 1D flexible silicon layer is formed at the top of the proposed structure. The proposed sensor is designed to measure the low pressure in the range of 10kpa to 20kpa. An FEM tool Comsol Multiphysics is used to design, simulate and analyze the structure. A central cavity is created to support the resonant mode and shift in the resonant mode is observed with the varying boundary load. With the variation in the applied pressure from 10kpa to 20kpa, shift in the resonant mode towards higher wavelength region was observed. The defect cavity length and number of layers were tuned to get optimized results. The novelty of this work includes, use of silicon material to sense the applied pressure, design and its simulation to obtain electric field distribution in the multi-layer structure and its analysis for sensing the applied boundary load using an FEM tool. Simulation results shows that the proposed sensor has a very high sensitivity of 350 nm/GPa and Q-factor of 40,104 with the transmission of 99.99 %.

Keywords

• Photonic crystal
• Pressure sensor
• Multi-layer structure
• FEM
• Transfer matrix