Optical Signal Processing
Abstract
A quasi-realtime adaptive processing system was used to correct the multipath distortion found in wideband digital radios. The measured power spectral density of the input signal was used to adaptively select one of eight equalization filters which reduce the residual distortion to less than 3.6 dB even for the most severe channel distortion. A related adaptive system was used for signal excision in which we removed narrowband interference from wideband signals with minimum signal distortion. We built an 8x8 acousto-optic switch in a multimode fiber-optic system. Insertion loss is approximately 2-4 dB, signal- to-crosstalk ratio is better than 25 dB, and the reconfiguration time is 880 nsec. We detected short pulses by using the Fresnel transform. We detected pulses as short as the theoretical limit of 20 nanoseconds for this system, and separated by as little as 60 nanoseconds or by as much as 17 nanoseconds. We considered all possible acousto-optic scanning configurations and classified them into four basic types. A consistent set of design relationships for each of the scanning configurations has been developed and presented in both tabular and graphic forms from which a preliminary design is obtained. Optical signal processing, Channel equalization, Adaptive optical processing, Fresnel transforms, Optical switches, Acousto-optics, Short pulse detection, Spatial filtering.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 30, 1993
- Accession Number
- ADA271036
Entities
People
- A. Vanderlugt
Organizations
- North Carolina State University