Signal Processing for Shearing Interferometer Measurements.
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OHIO SCHOOL OF ENGINEERING
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This paper provides a basic description of the operation of a shearing interferometer used for phasefront sensing. The signal processing of the interferometers outputs are studied. A basic demodulation scheme and a phaselocked loop configuration are discussed and compared. Some elementary phaselocked loop theory is provided. A possible configuration using optical feedback for determining off-axis tilt of a plane is presented. The signal-to-noise ratio of the shearing interferometers outputs is improved by a slight modification of the optical configuration. Finally, a geometric representation of a distorted phase profile is provided which will describe the deleterious effects of a planar phasefront propagating through the turbulent atmosphere. Author
- Atmospheric Physics
- Optical Detection and Detectors