Hempel, M.M.HempelTomm, J.W.J.W.TommBaeumler, MartinaMartinaBaeumlerKonstanzer, HelmerHelmerKonstanzerMukherjee, J.J.MukherjeeElsässer, T.T.Elsässer2022-03-112022-03-112012https://publica.fraunhofer.de/handle/publica/37581110.1117/12.9059452-s2.0-84857482081Many applications such as pumping of solid state lasers or ignition of explosives require high optical output powers during a short period. Pulsed operated diode lasers meet these requirements. They can be driven at elevated power levels, well above the ones specified for continuous wave (cw) operation. The optical near-field intensity of a diode laser in this operation regime is a key parameter since it determines the beam properties of the device. High power AlGaAs/GaAs quantum well broad area diode lasers are subjected to single pulse step tests carried out up to and beyond their ultimate limits of operation. Laser near-fields are monitored on a picosecond time scale using a streak-camera setup during pulse currents of up to ~50 times the threshold current. A transition from gain guiding to thermally-induced index guiding of the near-field is shown. Further power increase is prevented by catastrophic optical damage (COD). This sudden failure mechanism is studied in conjunction with filamentary properties of the near-field. The defect growth dynamics resolved on the picosecond time scale is used to gather inside into the physics behind COD.enhigh power broad area diode lasersnear-fieldfilamentationdegradationcatastrophic optical damage667conference paper