Semiconductor lasers generate a significant amount of heat during operation, which causes a number of undesirable effects including increasing the current necessary for a given emission intensity and shorter device lifetime. Especially quantum cascade lasers (QCL) are sensitive to temperature, which results in a reduction in light emission or a cessation of laser operation. <br><br> <strong>Technology</strong><br> The QCL consists of an active zone which comprises a cascade structure and an insulating heat-dissipating zone which is laterally adjoined to the active zone. The active zone, which generates heat, is made from a semiconductor material with high crystalline order. The insulating heat-dissipating zone is made from an electrically insulating, heat conducting material which is identical to the semiconductor material of the active zone. The electrically insulating property of the heat-dissipating material is based on a reduced level of crystalline order compared to the semiconductor material of the active zone. The crystal defects result from growth on an underlying amorphous film. The pre-patterned substrate is made of a robust amorphous material and is able to withstand temperatures of growth and processing up to ~ 600 °C. The active regions are defined prior to epitaxy so that the processing is largely finished (except for metallization) when the structure emerges from the epitaxy reactor. <br><br>
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