Large laser slabs were manufactured from Yb:YAG doped crystals for Diode-Pumped Solid State Laser (DPSSL) system Amos, which operates within Extreme Light Infrastructure in the Czech republic (ELI Beamlines). The dimension of the largest Yb:YAG laser slab produced is 120×120×8 mm, there is no visible stress under crossed polarizers and the wavefront distortion in the clear aperture region is smaller than λ/10 (λ=633 nm) in its Peak-to-Valley value. The edges of the slab are from diffusively bonded Cr:YAG cladding in order to suppress ASE (Amplified Spontaneous Emission).
In 2018 the performance of three sets of laser slabs (ø55x5 mm) with differently realized ASE suppression was characterized at cryogenic temperatures at HiLASE Centre in terms of small signal gain measurements as well as amplification test under 30 J pumping at 1 Hz and 10 Hz repetition rates. We provide data that show that the crystal slabs have comparable properties to the ceramic slabs (produced by Konoshima company, Japan) currently in use at HiLASE.