20  kW class high-beam-quality CW laser amplifier chain based on a Yb:YAG slab at room temperature

Abstract

A continuous-wave-operation laser amplifier chain consisting of three multi-concentration-doped Yb:YAG slab gain modules (GMs) at room temperature is presented. The output power of 22.3 kW with the beam quality of 3.3 times the diffraction limit is achieved from this chain. To the best of our knowledge, based on a Yb:YAG slab at room temperature, the highest power to date while maintaining excellent beam quality laser output. An extraction efficiency of 36% from the single slab GM is obtained and can be further enhanced to 46% by optimizing the parameters of GM. These results have confirmed that the Yb:YAG slab has an excellent scaling performance and is suitable for the development of high-average-power lasers.

High‐entropy transparent ceramics: Review of potential candidates and recently studied cases

“…Another way to solve this problem is to have an undoped cladding layer to help conduct heat toward the cooling system. The cladding layer helps to maintain high pump density and could also serve as a waveguide 112 . Three typical compositional structures for ceramic lasers are shown in Figure 15.…”

“…The cladding layer helps to maintain high pump density and could also serve as a waveguide. 112 Three typical compositional structures for ceramic lasers are shown in Figure 15. The slab structure has a bulk rare earth element doped ceramics region in the center and an undoped outer region.…”

22 kW near-diffraction-limited Yb:YAG slab laser amplifier without adaptive optics correction

“…In the same year, Wang et al reported a three-stage Yb:YAG CCEPS MOPA chain with an AO system, realizing 22.3 kW output with β enhanced from 9.2 to 3.3. The second 30-mm-width SGM in the main amplifier was extracted with a maximum power of 11.3 kW [16] . In 2020, Huang et al used a four-stage Yb:YAG slab AO-controlled MOPA system, obtaining 21.2 kW laser with a horizontal beam quality (HBQ) improved from 4.2 to 1.9.…”

High power and high beam quality quasi-continuous-wave pumped slab laser

“…Moreover, the amplifier has many components, the optical path is complex and the experimental cost is expensive. The slab laser improves the thermal effect of the gain medium from the geometric structure and cooling method [14][15][16].It has a large cooling surface area and a temperature gradient and thermal stress distribution that only exists in the thickness direction, and there is no temperature gradient distribution in the non-optical direction perpendicular to the thickness direction. This can significantly reduce the thermal depolarization effect and thermal birefringence effect, thereby reducing the impact on beam quality.…”