Signal Processing for Shearing Interferometer Measurements.
Abstract
This paper provides a basic description of the operation of a shearing interferometer used for phasefront sensing. The signal processing of the interferometer's 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 interferometer's 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)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1978
- Accession Number
- ADA064043
Entities
People
- Patrick J. Martone
Organizations
- Air Force Institute of Technology