Optical Excision Program. Holographic Local Oscillator
Abstract
a new technique for coherently detecting optical signals has been demonstrated in the laboratory. Prior to this work, conventional interferometer techniques were the only method by which the amplitude and phase of an optical signal could be measured, but the mirrors and beam-splitters required careful alignment and introduced a susceptibility to microphonic noise and laser coherence effects. Reported here are the results of an effort to design process, and evaluate holograms capable of producing the optical local oscillator needed in coherent, realtime optical signal processors. For more than a decade it has been known that an optical spectrum analyzer that has an acousto-optical input transducer can reconstruct the signal by coherently detecting the signal spectrum. This type of processor provides the capability to continuously form the spectrum of a signal, modify the signal spectrum, and then output a time- waveform signal reconstructed from the modified spectrum. This capability has been overlooked for the past decade partly because of the modest performance of the optical components needed in the processor. Recent advances in Bragg cell and detector technology now permit the development of wideband, high-resolution optical processors with performance orders to magnitude beyond that forecasted for future digital signal processors.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1979
- Accession Number
- ADA086912
Entities
People
- Dave Jackson