High sensitivity sensing system theoretical research base on waveguide-nano DBRs one dimensional photonic crystal microstructure

Abstract In this paper, we propose a novel wavelength modulation system dedicated to improve the performance of the integrated silicon microsensor. This system includes light source, waveguide, distributed Bragg reflectors (DBRs) and optical spectrum analyzer. Here, the silicon waveguide and two nano DBRs were designed to be one dimensional photonic crystal structure, which can implement wider modulation range in the photonic band gap. The rigorous coupled wave analysis (RCWA) method was used to quantitatively calculate transmissivity of each wavelength photon, and then spectral data in different displacement were obtained. By analyzing the defect modes in the spectrum, typical performance indicators of this modulation system are demonstrated as follows: The wavelength defect mode can be modulated from 1. 2 μ m to 2. 7 μ m , corresponding displacement is from 0 to 1. 5 μ m ; System sensitivity is up to 1.23-1.41, linearity ranges from 0.99 to 0.9999 for order 1 defect mode; The minimum peak transmittance of defect mode is greater than 0.68 based on 1 pm wavelength calculated step. Compared with the same type of system reported, the performance indicators have obvious advantages, and it is expected to directly improve the sensor performance by combining with the existing micro-mechanical structure.