Transient and long-term catastrophic optical damage in high power AlGaAs/GaAs laser diodes

The phenomenon of transient and long-term COD was studied experimentally by means of thermal infrared imaging, laser scanning confocal microscopy, and transient thermal technique. The long-term COD occurs in practical operation of high power laser diode, and the melting spots were observed in output facet, as well dark line defects appeared in cavity of high power laser diodes. Meanwhile, the transient COD occurred with the input current. We have recorded the dynamics of COD process using thermal infrared camera. The temperature of transient COD has a sudden increase of 32.07 °C when the COD event occurs which maintains less than 8.69 ms. It was found that the thermal resistance of chip increases remarkably after COD, meanwhile the thermal resistance of solder and package does not change apparently.