Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Near-field characteristics of broad area diode lasers during catastrophic optical damage failure

: Hempel, M.; Tomm, J.W.; Baeumler, M.; Konstanzer, H.; Mukherjee, J.; Elsässer, T.


Panajotov, K.; Sciamanna, M.; Valle, A.; Michalzik, R. ; Society of Photo-Optical Instrumentation Engineers -SPIE-, Bellingham/Wash.:
Semiconductor Lasers and Laser Dynamics V : 16 April 2012, Brussels, Belgium
Bellingham, WA: SPIE, 2012 (Proceedings of SPIE 8432)
ISBN: 978-0-8194-9124-4
Paper 84320O
Conference "Semiconductor Lasers and Laser Dynamics" <5, 2012, Brussels>
Fraunhofer IAF ()
high power broad area diode lasers; near-field; filamentation; degradation; catastrophic optical damage

One of the failure mechanisms preventing diode lasers in reaching ultra high optical output powers is the catastrophic optical damage (COD). It is a sudden degradation mechanism which impairs the device functionality completely. COD is caused by a positive feedback loop of absorbing laser light and increasing temperature at a small portion of the active material, leading to a thermal runaway on a nanosecond timescale. We analyze commercial gain-guided AlGaAs/GaAs quantum well broad area diode lasers in single pulse step tests. The near-field emission on the way to and at the COD is resolved on a picosecond time scale by a streak-camera combined with a microscope. In the final phase of the step tests the COD is occurring at ~50 times threshold current. The growth of the COD defect site is monitored and defect propagation velocities between 30 and 190 m/s are determined. The final shape of the damage is verified by opening the device and taking a micro-photoluminescence m ap of the active layer.