A Novel Differential Optical MEMS Accelerometer Based on Intensity Modulation, Using an Optical Power Splitter

In this paper, a novel highly sensitive differential optical MEMS accelerometer based on intensity modulation is proposed by using dual optical outputs and a two-dimensional (2D) photonic crystal power splitter. A TM-polarized light source, an optical power splitter (OPS) based on 2D photonic crystal (PhC), two typical photodiodes (PDs) and three optical ports build up the optical sensing system of the proposed sensor. The functional characteristics of the proposed device based on simulation results are as follows: Mechanical sensitivity of 0.0750 nm/g, linear measurement range of ±200 g, first mechanical resonance frequency of 17.7 kHz, optical sensitivity of 4.38 %/nm with bandwidth at half maximum (FWHM) of 1 nm (0.13 THz) at optical central wavelength of 1.495 μm (200.7 T Hz). This results in an optical quality factor of 1495 and total sensitivity of 0.3285 %/g. Due to the mentioned functional characteristics, the proposed sensor can be appealing for a wide range of applications, from inertial navigation and automotive to consumer electronics.