Temperature dependence of Alexandrite effective emission cross section and small signal gain over the 25-450 degrees C range

Abstract

We present detailed measurements of effective emission cross section spectra of the Alexandrite gain medium in the 25-450 degrees C temperature range and provide analytic formulas that can be used to match the measured spectra. The measurement results have been used to investigate the wavelength and temperature dependence of small signal gain, as well as gain bandwidth relevant for ultrafast pulse generation/amplification. We show that the estimated laser performance based on the measured spectroscopic data provides a good fit to the results in the literature. We further discuss the need for a detailed measurement of excited-state absorption cross section in future studies.