Reflectivity Changes of Germanium Due to Intense Radiations of Unequal Frequencies.
PENNSYLVANIA STATE UNIV UNIVERSITY PARK APPLIED RESEARCH LAB
Pagination or Media Count:
Changes in the reflectivity of germanium as a function of irradiation light intensity up to 6 Mssq 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 samples 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.
- Inorganic Chemistry