Variation of Refractive Index during Laser Operation.
Abstract
The effect on the efficacy of the Kronig-Kramers relations of non-Boltzmann population distributions established by optical pumping in pink ruby has been studied. The technique employed uses a ruby laser source which is frequency scanned across the Rl region of anomalous dispersion. The sample is in the form of a Fabry-Perot etalon and refractive index changes are determined from shifts in the fringe pattern which it produces. The experiments are conducted at liquid nitrogen temperature, and the sharpness of the Rl absorption structure at 77K has made it necessary to investigate the mode structure of the source laser and perform a complicated source-structure correction on the index measurements, or alternatively, to develop a single-mode, tunable, ruby laser source. Both approaches have been used. The occurrence of significant ground state depletion in some of the experiments and the substantial perturbation of the observed absorption profile produced even by very weak off-center modes make the simultaneous observation of the absorption and refractive index profiles necessary. A second method of measuring anomalous dispersion using a Babinet compensator has also been employed. The experiments are still in progress and the report discusses the techniques which have been developed and describes pertinent experimental observations rather than presenting definitive data correlating the real and imaginary parts of the complex refractive index of an optically pumped sample. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1970
- Accession Number
- AD0715412
Entities
People
- Jerald R. Izatt
Organizations
- New Mexico State University