PROCEEDINGS ARTICLE | March 18, 2016
Proc. SPIE. 9766, Vertical-Cavity Surface-Emitting Lasers XX
KEYWORDS: Microelectromechanical systems, Diffraction, Mirrors, Interferometers, Sensors, Interferometry, Capacitance, Microopto electromechanical systems, Integrated optics, Vertical cavity surface emitting lasers, Gyroscopes, Motion measurement, Michelson interferometers, Diffraction gratings
We report on the development of single-frequency VCSELs (vertical-cavity surface-emitting lasers) for sensing the position of a moving MEMS (micro-electro-mechanical system) object with resolution much less than 1nm. Position measurement is the basis of many different types of MEMS sensors, including accelerometers, gyroscopes, and pressure sensors. Typically, by switching from a traditional capacitive electronic readout to an interferometric optical readout, the resolution can be improved by an order of magnitude with a corresponding improvement in MEMS sensor performance. Because the VCSEL wavelength determines the scale of the position measurement, laser wavelength (frequency) stability is desirable. This paper discusses the impact of VCSEL amplitude and frequency noise on the position measurement.
