What is the lifetime of the laser (MTBF)?

At present only extrapolated lifetime experiments have been performed and they show more than 10 years extrapolated lifetime at 20C. The measurements have been done operating devices under N2 atmosphere at 130C in pulsed mode at 130% of threshold current. (An activation energy of 0.7 eV has been used to convert the high temperature life time of 350 to 500 hours to room temperature life time.)