Thermal properties and degradation behavior of red-emitting high-power diode lasers

The thermal properties and the degradation behavior of high-power broad-area diode lasers emitting at 650nm are analyzed. Imaging thermography is applied to assess the bulk temperature while the facet temperature is measured by micro-Raman spectroscopy. Although no visible facet alteration is observed, power degradation is found to be accompanied by increased temperatures at the facets. The immediate vicinity of them also turns out to be the starting point for the creation of defect networks within the quantum well seen in cathodoluminescence images. The observed behavior is compared to that known for near-infrared emitting devices.