SKM 2023 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 12: Semiconductor lasers I

HL 12.1: Talk

Monday, March 27, 2023, 15:00–15:15, POT 112

Adjustment of the active region on an InGaAsP VECSEL around 760nm for red pumping — •Rebecca Rühle, Marius Grossmann, Michael Jetter, and Peter Michler — Institut für Halbleiteroptik und Funktionelle Grenzflächen, Center for Integrated Quantum Science and Technology (IQST) and SCoPE, Universität Stuttgart, Allmandring3, 70569 Stuttgart, Germany

The quantum defect between the emission and the pump wavelength of vertical external-cavity surface-emitting lasers (VECSEL) has a huge impact on the performance of the structure. Especially to improve the thermal behavior, a longer wavelength pump laser is favorable. For the InGaAsP quantum well (QW) VECSEL with an emission wavelength at around 760nm, a pump laser at 675nm is preferable to one at 532nm. But the QWs are embedded in GaInP-barriers, thus are transparent for the pump light and the pump efficiency is rather small. To overcome this the composition of the GaInP can be changed so that the barrier again can absorb the pump light. The effects of adjusting the barrier in the active region and the performance of the VECSELs have now been investigated in detail. Photoluminescence and laser output power measurements were performed to compare the behavior of the different structures. A further study was carried out to evaluate the effect of the different gallium to indium ratio in the crystal structure on the surface roughness of the device.