Accession Number : AD0675313

Title :   EMISSION BANDWIDTH OF RUBY LASERS (O SHIRINE SPEKTRA GENERATSII OKG NA RUBINE),

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Sarzhevskii,A. M. ; Khomich,M. I.

Report Date : 06 DEC 1967

Pagination or Media Count : 6

Abstract : The emission bandwidth of ruby lasers with polished and frosted surfaces and with and without external mirrors was experimentally investigated at various distances between mirrors and at various levels of pumping energy. An IT-28 interferometer was used to measure spectral line width. The bandwidth of laser rods (80 mm long and 6.5 mm in diameter with coated ends narrowed linearly from 0.21 to 0.13/cm as the pumping energy increased from 400 to 1200 j. Two emission frequencies approximately 0.75/cm apart were observed when 0.4 cm thick external mirrors were used instead of the dielectric coatings which is in agreement with theoretical data. The number of frequencies is a function of mirror thickness. Thus, four frequencies 0.24/cm apart were generated with mirrors 1.2 cm thick. Only one frequency is observed at a mirror thickness of 0.3 cm, a case similar to that with coated rod ends. The frequencies come closer as the distance between the mirror increases. Frosting of the rod surface reduces the line width by a factor of two for the same pump level. The difference between the laser frequencies is independent of pumping energy. Thus, the external mirror acts as a frequency selector for the axial modes and only those modes which correspond to an integral number of half-waves on the mirror substrate are excited.

Descriptors :   (*LASERS, BANDWIDTH), RUBY, SPECTROSCOPY, OPTICAL PUMPING, MIRRORS, USSR

Subject Categories : Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE