Fig. 3: Test of the optical grating-based displacement measurement unit.
From: A μGal MOEMS gravimeter designed with free-form anti-springs
a Schematic of the displacement measurement via an optical grating cavity, which comprises a pair of gold grid lines. The displacement of the proof mass along the y-axis results in the variation in the light intensity of the interferometric diffraction beam, as shown in the inset. The period of the light intensity versus displacement is equal to the period of the metal gratings. b Photograph and schematic of the optical displacement measurement setup based on a piezoelectric ceramic. c Static results of the output voltage versus the input displacement. d Noise performance of the optical displacement measurement unit.
