Pulsed broadly tunable room-temperature Cr2+:CdS laser

Abstract

We report the spectroscopic characteristics and laser properties of Cr2+:CdS. The emission lifetime of the exited state, 5E, of Cr2+ in CdS host was measured to be 0.93 µs at room temperature and 7.3 µs at liquid nitrogen temperature. The measured values of peak absorption and emission cross sections were found to be 1.4×10−18 and 1.1×10−18 cm2 respectively. Room-temperature pulsed-laser operation was obtained under pumping by the 1.94 µm output of a Tm:YAP laser. The output of the free-running Cr2+:CdS laser was centered at ∼2.6 µm, and an absorbed energy slope efficiency of 38.8% was demonstrated. The passive crystal losses were measured to be less than 0.049 cm−1 at the lasing wavelength. With an intracavity prism, the Cr2+:CdS laser was tuned from 2.18 to 3.32 µm.