High-efficiency 660-nm VCSEL exhibiting 26.47% peak wall-plug efficiency and improved high-temperature performance up to 65°C.

We demonstrate a high-performance 660-nm vertical-cavity surface-emitting laser (VCSEL) employing a strain-compensated GaInP/AlGaInP active region and an asymmetric AlGaAs distributed Bragg reflector (DBR). By engineering a -10 nm room-temperature spectral detuning (λgain - λcavity), we compensate for the differential thermal redshift between the gain peak (0.26 nm/K) and the cavity mode (0.035 nm/K). This spectral realignment mitigates the severe Γ-to-X intervalley carrier leakage inherent to the AlGaInP system, sustaining high conversion efficiency at elevated temperatures. The fabricated device achieves a peak wall-plug efficiency (WPE) of 26.47% for 660-nm VCSELs and a continuous-wave output power of 19.11 mW at 300 K. The high efficiency is supported by reduced series resistance via graded DBR interfaces, which enhance thermionic-field emission and mitigate resistive heating. At 340 K, the VCSEL retains a WPE of 11.36% and maintains 40.87% of its room-temperature output power under 15 mA injection. These results demonstrate a robust design strategy for thermally stable red VCSELs in biophotonic and laser-display applications.