Coherence Properties of Broadband Optical Fields with Applications to White-Light Shearing Interferometry.
Abstract
A free-space propagation model for broadband optical fields is developed based on a Karhunen-Loeve (KL) expansion of the time-varying portion of a coherence separable broadband optical envelopee. The resulting model expansion provides an intuitively simple interpretation of the propagation of broadband fields, and allows the output field correlation to be easily calculated. The propagation model is applied to the analysis of a lateral shear AC interferometer, which has been used to measure the spatial phase variations of a white-light optical field envelop located at its input aperture. It is found that the interferometer's operation for broadband fields causes the phase which is measured by the interferometer to be related to a spatially filtered version of the aperture field. The propagation model is applied to the shearing interferometer's operation as a wavefront sensor in a phase-compensated imaging system, where the phase of the aperture field envelope has been disrupted by atmospheric turbulence. The turbulence-induced phase perturbation is modeled as a unit-modulus phase screen introduced at the aperture plane of the interferometer for each temporal mode of the field expansion. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1978
- Accession Number
- ADA064404
Entities
People
- Paul S. Idell
Organizations
- Air Force Institute of Technology