Hybrid approach to two-dimensional surface-emitting diode laser arrays

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Abstract
A new hybrid structure for two-dimensional surface-emitting diode laser arrays has been demonstrated. Each hybrid array consists of linear arrays of GaAs/AlGaAs lasers, with conventional cleaved end facets, that are mounted in grooves etched in a Si substrate. The etched grooves have flat bottoms and 45° sidewalls that are coated with a highly reflecting Cr/Au layer. A hybrid array with three 4-mm-wide GaAs/AlGaAs linear laser arrays has been fabricated and tested. Approximately 10 W of peak power perpendicular to the array surface was obtained from each of the linear arrays for 11–12 A of pulsed current per array. The measured differential quantum efficiencies were 65–70%, indicating that the 45° metallized sidewalls deflect by 90° essentially all of the light emitted from the laser facets. The new approach allows for the use of integral Si heat sinks and should prove useful for fabricating large, high-power, two-dimensional laser arrays in any material system.