Reflectivity Changes of Germanium Due to Intense Radiations of Unequal Frequencies.
Abstract
Changes in the reflectivity of germanium as a function of irradiation light intensity up to 6 Ms/sq cm were used as a method of studying tempory diffraction gratings. This method utilizes an intense, or pumping, laser beam and a weak, or probing, laser beam both of which were produced from the same ruby source. They were used at small angles of incidence and were coincident at the sample's surface. The frequency of the probing beam was made slightly different from that of the pumping beam by one of two nonlinear backscattering processes, stimulated Brillouin scattering (SBS), or stimulated thermal Rayleigh scattering (STRS). When the planes of polarization of the two beams are parallel, the effects of interference will cause a spatial and temporal variation in the optical properties of the germanium surface producing a surface wave.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 09, 1978
- Accession Number
- ADA059427
Entities
People
- Arthur H. Carrieri
Organizations
- Pennsylvania State University