1.3. Life time of a semiconductor laser as a function of current

There is an empirical relation between current and specified life time

L_op = L_spec * (I_op / I_spec)^(- n)

where n is a factor between 1.5 and 2.0 for  laser diodes base on GaAs.The factor n has to be determined for experimentally by doing sample life time measurements for a each batch of diodes. Assuming a factor of 1.5, a reduction of the operating current to half of the maximum rated current would increase the lifetime by a factor of 2.8, for example.