What influences the life time of a laser diode?
Thermal stress can induce mechanical stress due to the different temperature coefficients of the components. This can cause the growth of crystal defects or put a strain on the connections inside the laser device. Both effects can shorten the life time of the laser device. A momentary over current of the laser driver can damage the laser. A laser pulse with extremely high peak power and the high current concentration can destroy or at least predamage parts of the facet. Optical absorption at this defect can cause nonradiative recombination and lead to heating and melting. The higher temperature at the surface decreases the band gap leading to a current concentration at the defect. This increases the heating again and results finally in a catastrophic optical damage (COD).
