Annealing effects on multi-quantum well laser diodes after proton irradiation

The threshold current of multi-quantum well laser diodes increased by about 1.5 mA at a proton fluence of 6×10¹² p/cm². It recovered gradually due to forward-bias annealing at I_bias=35 mA and became about 0.8 mA less than before irradiation after 86 h of forward bias annealing. At the same time, the optical power at a given bias became greater than before irradiation. There is a fast recovery during the first 100 s after proton irradiation. Increasing the forward bias current during annealing speeds up the annealing process. The degradation of optical power at a proton flux of 1.87×10⁹ p/cm²/s (4.7% at a fluence of 6×10¹² p/cm²) is less than that at a proton flux of 1.45×10¹⁰ p/cm²/s (10.5% at a fluence of 6×10¹² p/cm²) due to the in-situ forward-bias annealing effects