A Spatially Incoherent and Temporally Coherent Source.
Abstract
The ability to create is spatially incoherent and temporally coherent sources is a major military concern when considering atmospheric turbulence effects on laser beam propagation. Young's double slit experiment is used to measure the degree of spatial coherence of the source when various diffusive materials are placed between the laser and double slit. A photo-multiplier tube is used for detection of an argon-ion laser signal. Experimental results show that the spatial coherence of the source is affected signigicantly by the location of the diffusive materials and the size of the laser beam. For this particular experimental geometry, opal glass placed 17 cm from the double slit degrades the spatial coherence of the source by 99.5%. By expanding the beam diameter 2 1/2 times the original size, the spatial coherence of a diffused beam is decreased by an average of 95% over a 10 cm region. In addition to experimental observations, the applicable sections of partial coherence theory are discussed. Keywords include: Spatially incoherent light source, and Young's double slit experiment.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1984
- Accession Number
- ADA151281
Entities
People
- J. S. Peterson
Organizations
- Naval Postgraduate School