Multi-Wavelength, Efficient Mid-Infrared Laser System

摘要

The objective of this project was to investigate the feasibility of producing radiation at multiple wavelengths from a single solids state laser medium. We investigated holmium doped YLF and BYF. Both the growth of boules and single crystal fiber growth were investigated. Laser quality boules of high Ho concentration were grown. Although single crystal fibers were grown, they were not of laser quality due to oxygen contamination. Improvements in the laser modeling of this system were made which included cross relaxation of several levels and resonant pumping of more than one level. Cascade laser action was investigated with the model which incorporated the measurement of several absorption cross sections, fluorescence lifetimes and cross relaxation rates that were measured during the course of the program. In laser tests, lasing was obscene at 1.4 micrometers and 750 nm with very low thresholds observed at 1.4 micrometers.