High power single crystal KTA optical parametric amplifier for efficient 1.4–3.5 µm mid-IR radiation generation

Abstract In this paper, we present a single crystal, KTA (potassium titanyl-arsenate, KTiOAsO4) based picosecond optical parametric amplifier pumped by an in-house built 1030 nm Yb:YAG thin-disk laser, capable of tunability from 1.46 to 3.5 µm, operating at 90 kHz, with high average power in the signal and idler beams. The highest output power of 8.9 W was reached for the 1750 nm signal beam with 19% conversion efficiency and the respective 2500 nm idler beam power was 6.2 W with 13% efficiency. The highest combined signal and idler mid-infrared power was 17 W at the 2060 nm wavelength degeneracy point.