Accession Number : ADP006699

Title :   Photorefractive Properties of Bi sub 4 Ge sub 3 O sub 12 Crystals in the Ultraviolet Spectral Range.

Corporate Author : ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (SWITZERLAND)

Report Date : 22 MAY 1992

Pagination or Media Count : 4

Abstract : To the best of our knowledge, only preliminary studies of photorefractive effects in the ultraviolet (UV) spectral range have been reported up to now, e.g. in KH2PO4, RbZnBr4 (both at low temperatures), and in LiNbO3 and LiTaO3 in the near UV. Photorefractive materials operating in the UV however could be very useful for all types of coherent optical beam interactions, e.g. beam amplification, dynamical holography, phase conjugation or photolithographic applications where the use of shorter wavelengths leads to an increased resolution. Bi4Ge3Ol2, the material used in this work belongs to the cubic point group 43m and has a large transparency range extending from about 300 nm to about 6 micron m. In the visible spectral range, photorefractive effects have been observed recently in Cr doped Bi4Ge3Ol2 by Moya et al., who first proposed the material as a candidate for UV photorefraction. In this work we report on the observation of photorefraction in undoped Bi4Ge3Ol2 and present a detailed characterization of photoinduced refractive index changes, the absorption constant, the photoconductivity and the dispersion of the electro-optic coefficients all in the UV spectral range.

Descriptors :   *ULTRAVIOLET SPECTRA, *COHERENT OPTICAL RADIATION, ABSORPTION, AMPLIFICATION, DISPERSIONS, HOLOGRAPHY, INTERACTIONS, OPTICS, PHOTOCONDUCTIVITY, REFRACTIVE INDEX, RESOLUTION, TRANSPARENCIES, ELECTROOPTICS, LITHIUM, PHOTOLITHOGRAPHY, PHOTONICS, SHORT WAVELENGTHS, SYMPOSIA.

Subject Categories : Optics
      Electrooptical and Optoelectronic Devices

Distribution Statement : APPROVED FOR PUBLIC RELEASE