Analysis of optical and thermal properties of 940-nm vertical-cavity surface-emitting lasers

We achieve 13.5 mW optical output power, 48% power conversion efficiency, 1.17 W/A slope efficiency and 17 kW/cm2 laser power density with top-surface-emitting 940 nm oxide-confined vertical-cavity surface-emitting laser (VCSEL). The physical mechanism of minimum threshold current generation in oxide-confined VCSEL has been thoroughly studied theoretically and experimentally. Further, we also succeeded in 90.8 mW optical output power, 40% power conversion efficiency with 2 × 4 VCSEL arrays. We find an increase in output power and PCE of 2 × 2 VCSEL arrays as we increase the array spacing which we attribute primarily to increased heat dissipation and reduced thermal crosstalk between the emitters. Thermal properties in oxide-confined 2 × 2 VCSEL arrays were analyzed numerically and experimentally. The simulated results are in good agreement with the measurement. It is proved that theoretical simulation is very useful for the future device optimization.