High-Efficiency High-Repetition-Rate Gain-Switched Operation Around 3 μm in Cr2+:CdSe Single-Crystal Laser Pumped by Fiber-Laser-Pumped Ho3+:YAG Laser at 2.1 μm

The expansion of laser sources operating near 3 μm is motivated in large by their strong absorption in several gases, liquid water, and plastics, critical for applications in remote sensing, soft and hard tissue surgery, and materials processing [1,2]. Both CW and pulsed operations were demonstrated in Cr
²⁺
:CdSe lasers with wide tunability range spanning from 2 μm to 3.6 μm. Different pump sources were used, such as Tm
³⁺
- and Tm
³⁺
,Ho
³⁺
-doped crystal lasers, diodes and Tm-fiber lasers [3,4]. The relatively short lifetime of the upper laser level and low damage threshold of Cr
²⁺
:CdSe crystal surface limit maximum pulse energy and average power in the repetitively-pulsed Cr
²⁺
:CdSe oscillators [2-4]. The highest average power achieved so far in the Cr
²⁺
:CdSe lasers was less than 1 W at kHz pulse repetition rate (PRR). In this report, we present an efficient high-repetition-rate Cr
²⁺
:CdSe single-crystal laser operating around 3 μm with the output power of up to 6 W and pumped at 2.1 μm by a fiber-laser-pumped Ho
³⁺
:YAG laser.