Observation of the Photorefractive Effect in Semi-Insulating Cds,
Abstract
Considerable attention has been devoted to the identification of fast and sensitive photorefractive materials in the last decade. Materials such as Bi20SiO20, gallium arsenides, indium phosphides:iron gallium phosphides and cadmium tellurides:vanadium are characterized by relatively large diffusion lengths and fast response times at incident intensities of few tens of mw/sq.cm. However, with the exception of GaP none of these materials can be used in the wavelength range of 600-700 nm. Cadmium Sulfide (CdS) has been extensively investigated as a photoconductor but to the best of our knowledge investigations on it photorefractive properties have not yet been reported. This paper reports the observation of moderate gain 0.3/cm. in low loss (0.14/cm) single crystals of CdS at a wavelength of 633 nm. At the same wavelength CdS is at least an order of magnitude more sensitive than GaP and in contrast to this material it offers net gain. The behavior of the gain coefficient as a function of grating period for ordinary and extraordinary polarizations has been investigated assuming a one charge carrier model. The photorefractive grating response time has also been determined.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 22, 1992
- Accession Number
- ADP006700
Entities
People
- D. Barman
- J. Kumar
- P. Tayebati
- Simon Scott