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.
The thermal behaviour of high-power GaAIAs/GaAs laser arrays is described by a comprehensive thermal two-dimensional finite-element model which takes several heat sources into account. The influence of these different heat sources on the two-dimensional temperature distribution in the laser array has been investigated. The power densities of the heat sources related to the active region were calculated by an analytic description of the temperature dependent processes as spontaneous emission, Auger recombination and interface recombination. The results of our numerical calculation show, that the local distribution of the heat sources has a strong influence on the lateral temperature profile and on the maximum temperature in the active region of the array, i.e. on the thermal resistance. The calculated temperature profiles are in a good agreement with the measured lateral temperatures at different injection currents and heat sink temperatures. The difference between calculated and measured maximum temperature is lower than 0.75"C.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.