Bibliographic Citation

 
7,355,720
Optical displacement sensor
View USPTO link (Link will open in a new window)
04/08/2008
US patent application 11/314,335
Carr, Dustin W. (Albuquerque, NM)
Sandia National Laboratories (SNL-NM), Albuquerque, NM
United States Department of Energy
AC04-94AL85000
Sandia Corporation (Albuquerque, NM)
An optical displacement sensor is disclosed which uses a vertical-cavity surface-emitting laser (VCSEL) coupled to an optical cavity formed by a moveable membrane and an output mirror of the VCSEL. This arrangement renders the lasing characteristics of the VCSEL sensitive to any movement of the membrane produced by sound, vibrations, pressure changes, acceleration, etc. Some embodiments of the optical displacement sensor can further include a light-reflective diffractive lens located on the membrane or adjacent to the VCSEL to control the amount of lasing light coupled back into the VCSEL. A photodetector detects a portion of the lasing light from the VCSEL to provide an electrical output signal for the optical displacement sensor which varies with the movement of the membrane.

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