Process and apparatus for filament or slit size monitoring
Optical method and apparatus for strain analysis
Compact portable diffraction moire interferometer
Method of optoelectronically measuring distances and angles Patent #: 5141317
ApplicationNo. 087501 filed on 07/02/1993
US Classes:356/484, Having light beams of different frequencies (e.g., heterodyning)356/28.5, Of light interference (e.g., interferometer)356/35.5By light interference detector (e.g., interferometer)
ExaminersPrimary: Turner, Samuel A.
Attorney, Agent or Firm
International ClassG01B 009/02
AbstractA method and apparatus for remotely measuring such physical properties as surface temperature and strain on or near the surface of an object such as an aerodynamic model utilizes a sensor comprising a holographic diffraction grating in a thin film, formed on or affixed to the surface of the test object, thereby forming an "optically smart surface." The sensor is remotely illuminated by one or more optical address beams, which are preferably coherent laser beams. Optical beams diffracted from the surface of the sensor produce interference patterns in a remote photodetection apparatus which permits measurement in changes in grating spatial frequency caused by temperature changes or mechanical deformations of the object surface, or Doppler measurement of particle velocity in a sample volume produced by intersecting beams diffracted from the sensor hologram.