Gain Analysis of a Compact Ho:YAG Slab Amplifier, End-Pumped by a High Power Tm:YLF Slab Laser

High-power and high-energy lasers at 2 μm are becoming increasingly important for materials processing applications where the mid-infrared laser wavelength provides a clear advantage. The use of a Master Oscillator Power Amplifier approach enables the scaling of the output power and energy beyond what is efficiently achievable from a single resonator with the desired beam properties. Here we present a compact, power scalable, Ho:YAG thin-slab gain module, pumped by a continuous wave Tm:YLF slab laser, that is suitable for multiple seed sources and could be set up in a single-, double- or multi-pass amplifier configuration. The numerical and experimental studies include spatial and temporal analyses of the gain provided by the thin-slab amplifier in continuous-wave, kHz ns-pulsed and MHz ultra-short-pulse operation.