Efficient Nd:YAG∖KTiOAsO4 cascaded Raman laser emitting around 1.2 μm

High-order Stokes around 1.2 μm generated by Nd:YAG∖KTiOAsO4 (KTA) cascaded Raman laser is presented. The fundamental and low-order (first to third) Stokes lines were well restricted in the cavity. The KTA Raman laser output starts with single Stokes emission at 1182 nm. As the incident pump power was increased, Stokes emission at 1178, 1216 and 1212 nm appeared in sequence. The total output power of 1.03 W and the conversion efficiency of 10.1% were obtained at the incident pump power of 10.2 W and the pulse repetition frequency of 15 kHz. The results show the cascaded Raman of KTA can enrich laser spectral lines and generate high-order Stokes light.