Temperature-Dependent Fluorescence Properties and Diode-Pumped Deep Red Laser Performance of Pr:LiGdF₄ Crystal

We demonstrate the temperature-dependent fluorescence properties of Pr:LiGdF₄ crystal for the first time, to the best of our knowledge, and its blue diode pumped cw red laser at 720 nm at room temperature. The fluorescence lifetime and polarized emission cross sections in the visible range are measured and calculated in a temperature range from 77 K to 300 K, and the variations of the fluorescence lifetime and spectra are discovered. The reasons for these changes are explained accordingly. The output wavelength of the 720 nm laser is first reported on the laser performance by using a fiber-coupled laser diode at the wavelength of 442 nm as the pump source, and the maximum cw output power is about 303 mW.