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PLZT block data composers operated in differential phase mode
- Publication Year :
- 1973
- Publisher :
- United States: NASA Center for Aerospace Information (CASI), 1973.
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Abstract
- The use of PLZT ceramics with the 7/65/35 composition in block data composer (BDC) input devices for holographic memory systems has previously been described for operation in the strain biased, scattering, and edge effect modes. A new and promising mode of BDC operation is the differential phase mode in which each element of a matrix array BDC acts as a phase modulator. The phase modulation results from a phase difference in the optical path length between the electrically poled and depoled states of the PLZT. It is shown that a PLZT BDC can be used as a matrix-type phase modulator to record and process digital data by the differential phase mode in a holographic recording/processing system with readout contrast ratios of between 10:1 and 15:1. The differential phase mode has the advantages that strain bias is not required and that the thickness and strain variations in the PLZT are cancelled out.
- Subjects :
- Electronic Equipment
Subjects
Details
- Language :
- English
- Database :
- NASA Technical Reports
- Notes :
- NAS8-26672
- Publication Type :
- Report
- Accession number :
- edsnas.19740031384
- Document Type :
- Report