Title :
Geometrical modulation-based interferometry for displacement sensing using optically coupled suspended waveguides
Author_Institution :
Dept. of Interdisciplinary Studies, Tel Aviv Univ., Israel
fDate :
9/1/1998 12:00:00 AM
Abstract :
A geometrical modulation-based interferometry (GMI) for a displacement sensor is presented. The implementation of the GMI is based on the suspended optical waveguide displacement sensors (SOWDSs) technology. The interferometry effect of the GMI results from light propagating in geometrically modulated and mutually coupled suspended waveguides with an in-plane degree of freedom. The building block of the suspended waveguides is a single-crystal silicon (SCS) beam with superficial layers comprising a 0.6-μm-thick SiO2, 0.4-μm-thick Si3N4, and 0.6-μm-thick SiO2. The SCS beam is fabricated with a cross section of 1.6 μm×10 μm and may guide light with wavelength in the 1.3-1.5-μm range. The first SiO2 layer serves as a buffer layer that allows light with wavelength in the 0.6-0.9-μm range to be guided in the Si3N4 layer. This paper discusses the theoretical consideration and the characterizations of a GMI displacement sensor
Keywords :
displacement measurement; integrated optics; light interferometry; optical modulation; optical planar waveguides; optical sensors; 0.4 micron; 0.6 micron; 1.3 to 1.5 micrometre; SOWDS; Si-SiO2-Si3N4; buffer layer; displacement sensing; geometrical modulation-based interferometry; mutually coupled suspended waveguides; optically coupled suspended waveguides; superficial layers; Geometrical optics; Mutual coupling; Optical buffering; Optical coupling; Optical interferometry; Optical modulation; Optical propagation; Optical sensors; Optical waveguides; Silicon;
Journal_Title :
Microelectromechanical Systems, Journal of
