The temperature behaviour of GaAdGaAIAs DQW-GRINSCH high-power laser diodes is calculated by means of a numerical model. The model includes a microscopic description of gain and spontaneous radiative recombination, a phenomenological description of interface and Auger recombination, and includes a pumping-current-dependent leakage. Based on the model, the temperature dependences of the macroscopic parameters of threshold current, external differential efficiency and wavelength are calculated. The resulting numerical values for these parameters are in excellent agreement with our experiments. Spontaneous radiative recombination is shown to be the dominant loss mechanism,

A numerical model is introduced that self-consistently calculates the time dependent axial variations of photon density, carrier density and temperature in semiconductor lasers. The most important approximations are outlined. In order to illustrate the capability of the model, some results are shown for an asymmetrically coated DQW GaAs/GaAlAs edge emitting laser diode. The temperature rise at the facets and the corresponding profiles of carrier and photon density are calculated. The asymmetric behaviour of the profiles is discussed. The heating is calculated as a function of surface recombination velocity at the mirrors and as a function of injection current. The calculations provide insight into the process of facet heating and catastrophic optical damage. The calculations are confirmed by experimental investigations.

Laser radiation from GaAs/AlGaAs laser diode arrays of high output power is studied during nano- to millisecond carrier injection in temporally and spectrally resolved emission measurements. A red shift of the multimode emission spectrum by up to 12 nm and a concomitant increase of the total bandwidth are caused by a transient rise of the device temperature by up to 50 K. Spatially resolved experiments reveal a lateral temperature difference of about 2 K between the center and the edge emitters. Different laser array/heat sink combinations are investigated in order to reduce the transient temperature increase.

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