Accession Number : ADP007864

Title :   Optically Encoded Second-Harmonic Generation in Semiconductor Microcrystallite Doped Glasses,

Corporate Author : BROWN UNIV PROVIDENCE RI DEPT OF PHYSICS

Personal Author(s) : MacDonald, R. L. ; Lawandy, N. M.

Report Date : 22 MAY 1992

Pagination or Media Count : 4

Abstract : Since the discovery of second-harmonic generation (SHG) in germanosilicate fibers no other materials have been found which exhibit optically organized X(2) gratings. We have discovered that CdSxSe1-x semiconductor doped glasses can be prepared for efficient SHG when the glass is simultaneously exposed to 532 nm and 1.06 um radiation from a Q-switched and mode-locked laser. Using 5 cm path length in a 530 nm bandgap filter we have observed a 10-6 conversion efficiency, which resulted in a green spot visible in room lights. The effect is permanent in some glasses and is a strong function of the position of the microcrystallite band-ap. The phenomenon poses a test to our basic understanding of electronic processes in nanocrystals and heterogeneous glasses and opens a door to new materials for frequency doubling laser sources. The experimental set-up consisted of a mode-locked, Q-switched and frequency doubled Nd:YAG laser, two polarizers, a 10 cm focussing lens, and a phase sensitive detection system capable of detecting 10-14 W of average power. The laser produced pulses which were 110 psec and 80psec long at 1-06 um and 532 um, respectively, with a 76 MHz mode-locking rate and a Q-switching rate of 1 kHz.

Descriptors :   *GLASS FIBERS, *FREQUENCY CONVERSION, *NONLINEAR OPTICS, DETECTION, EFFICIENCY, FIBERS, FREQUENCY, FUNCTIONS, HARMONICS, LENGTH, MATERIALS, PATHS, PHASE, POLARIZERS, POWER, PULSES, Q SWITCHING, RADIATION, RATES, SEMICONDUCTORS, TEST AND EVALUATION, CADMIUM SULFIDES, CADMIUM SELENIDES, MODE LOCKED LASERS, BANDPASS FILTERS, SILICA GLASS.

Subject Categories : Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE