Thermal Lensing Effect Reduction on High-Power Multi-Mode Diode Lasers

High-power broad-area diode lasers are needed for a variety of applications. However, such lasers suffer from deteriorated beam quality due to multimode behavior in the lateral direction at high power. We propose an approach to reduce the thermal lensing effect by introducing a thermal compensation layer. As a result of reducing the thermal lensing effect, we demonstrated that the lateral divergence angle was reduced by 16.2%, the lateral beam parameter product was reduced by 12.8%, and the lateral brightness was increased by 18.4% for $230 \mu \text{m}$ wide diode operating at 50 A current while maintaining a good output power.