Accession Number : ADP006700

Title :   Observation of the Photorefractive Effect in Semi-Insulating Cds,

Corporate Author : FOSTER-MILLER INC WALTHAM MA

Personal Author(s) : Tayebati, P. ; Kumar, J. ; Barman, D. ; Scott, S.

Report Date : 22 MAY 1992

Pagination or Media Count : 5

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.

Descriptors :   *PHOTOCONDUCTORS, *CADMIUM SULFIDES, ATTENTION, BEHAVIOR, CADMIUM, CHARGE CARRIERS, COEFFICIENTS, CONTRAST, CRYSTALS, DIFFUSION, FUNCTIONS, GAIN, IDENTIFICATION, MATERIALS, MODELS, NETS, OBSERVATION, RESPONSE, SINGLE CRYSTALS, TIME, SHORT WAVELENGTHS, GRATINGS(SPECTRA), SYMPOSIA.

Subject Categories : Optics
      Electrooptical and Optoelectronic Devices

Distribution Statement : APPROVED FOR PUBLIC RELEASE