Abstract

The conversion of photon energy into thermal energy by nonradiative relaxation processes causes the temperature of laser materials to rise. The use of calorimetry techniques to measure sample heating due to radiationless relaxation of excited states has been reviewed by Callis.¹ In the present study, laser calorimetry was used to determine the room-temperature fluorescence quantum efficiency of GSGG:Cr³⁺. A related technique employing an electronically compensated calorimeter was recently used to measure the fluorescence quantum efficiency for Cr³⁺ in lithium lime silicate glass and in ruby.² Other methods for measuring quantum efficiencies of ions in solids include photometric methods utilizing an integrating sphere³ and photoacoustic measurements.⁴ The advantage of laser calorimetry over the latter two methods is its relative ease of calibration.

© 1987 Optical Society of America