Frequency down-conversion of solid-state laser sources to the mid-infrared spectral range using non-oxide nonlinear crystals

Ultrashort pulse generation in the mid-IR

Lasers and Coherent Light Sources

Generation of tunable mid-IR (5.5–9.3 μm) from a 2-μm pumped ZnGeP2 optical parametric oscillator

Continuous wave (CW) and acousto-optical (AO) Q-switch operation of Tm (5 at.%), Ho (0.3 at.%):YAP laser at 2.13 μm wavelength were reported in this paper. The Tm,Ho:YAP crystal was cooled by liquid nitrogen and double-end-pumped by a 14.2 W fiber-coupled laser diode at 798 nm. Different resonator lengths and output couplers for the pump power were tried. A maximum conversion efficiency of 31.3% and a maximum slope efficiency of 35.2% were acquired with CW output power of 4.45 W. Average power of 4.21 W was obtained at pulse repetition frequency (PRF) of 15 kHz, corresponding to an optical-to-optical conversion efficiency of 29.6% and a slope efficiency of 32.4%. The energy per pulse of 2.3 mJ in 64 ns was achieved at 1.5 kHz with the peak power of 35.8 kW.

https://iopscience.iop.org/article/10.1002/lapl.200810105/pdf

Continuous wave and AO Q-switch operation Tm,Ho:YAP laser pumped by a laser diode of 798 nm

We demonstrate a high-efficiency ZnGeP2 optical
parametric oscillator (OPO) pumped by another KTP OPO in a
multimode-pumped tandem OPO configuration. The maximum
optical-to-optical and slope efficiencies were 32% and 42.5%,
respectively. Our setup also provides tunable multiband radiation
in the 2.03–2.32-µm range and the 2.9–6.2-µm range
simultaneously.

King Seng Lai

Papers

High-efficiency mid-infrared ZnGeP 2 optical parametric oscillator in a multimode-pumped tandem optical parametric oscillator