Asymmetric waveguide and compressively strained quantum well-enabled high-power, polarization-dependent 850 nm gain chip.

The development of high-power gain chips is crucial for advancing hybrid-integrated narrow-linewidth lasers, which face power limitations in emerging applications such as quantum sensing and atomic cooling. This study designed a high-power GaAs-based gain chip based on an asymmetric waveguide and compressively strained quantum wells for the 850 nm wavelength band. By applying the epitaxial structure and low-loss waveguide, a record continuous-wave output power of 114.08 mW and a broadband spectrum spanning 31.55 nm with low spectral modulation were achieved. Experiments have shown that the asymmetric waveguide significantly enhances power and reduces cavity loss by suppressing carrier leakage, while the compressive strain-induced valence band splitting enhances the polarization extinction ratio. This work provides a simple and direct option for developing high-power hybrid-integrated lasers in the 850 nm band.