Optical design and analysis of a high resolution MOEMS accelerometer based on diffraction grating

The design and analysis method of a MOEMS accelerometer consisting of a grating interferometry cavity and a micromachined sensing chip is presented in this paper. The grating interferometeric cavity is composed of a frequency-stabilized laser source, a diffraction grating, and a mirror ,to realize a subnanometer resolution. With an ultrasensitive micromachined chip, the MOEMS accelerometer can finally achieve a few ug resolution. This paper combines the geometrical optics and nano optics design methods to simulate the whole system, analyses how the divergence angle, grating constant and the length of the interferometeric cavity influence the ultimate sensitivity. A new set of MOEMS accelerometer is proposed, the theoretical analysis shows that the acceleration sensitivity can achieve 1200 v/g, and the resolution remains 1.3ug.