Photorefractive Properties of Bi sub 4 Ge sub 3 O sub 12 Crystals in the Ultraviolet Spectral Range.
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 22, 1992
- Accession Number
- ADP006699
Entities
Organizations
- Swiss Federal Institute of Technology in Lausanne