Semiconductor-laser thermal time constant

Thermal time constants of semiconductor lasers (‘‘test lasers’’) are measured by transient heating of test laser chips by use of another laser (‘‘pump laser’’). Pump laser emission impinging on the test laser p contact generates local heating. Thus, current-independent thermal responses are studied. Thermal time constants of 5.6 and 7.2 μs are measured and tend to confirm heat diffusion as the mechanism governing transient laser thermal behavior for times in the several microsecond range.