Berlin 2018 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 13: Poster Session I
HL 13.86: Poster
Monday, March 12, 2018, 17:30–19:30, Poster B
Characterization of high-efficiency AlGaInP VECSELs in a gain chip holder with optimized heat flow — •Alexander Peschken1, Hermann Kahle2, Roman Bek1, Cherry May Mateo3, Uwe Brauch3, Marwan Abdou Ahmed3, Michael Jetter1, Thomas Graf3, and Peter Michler1 — 1Institut für Halbleiteroptik und Funktionelle Grenzflächen, SCoPE, IQST, Univ. Stuttgart, Germany — 2Tampere Univ. of Technology, Finland — 3Institut für Strahlwerkzeuge, SCoPE, Univ. Stuttgart, Germany
Vertical external-cavity surface-emitting lasers (VECSELs) provide in principle power scalability at constant beam quality and vast wavelength flexibility. However, due to the limited charge-carrier confinement in AlGaInP-based VECSELs, an optimized heat extraction is essential in order to enable power scalability. Unfortunately, the substrate and the distributed Bragg reflector in such VECSELs show a low thermal conductivity. Hence, an additional intra-cavity heat spreader is inevitable to overcome occurring temperature problems. A modified chip holder with mechanically improved thermal contact between gain element and heat spreader showed already a doubling of the maximum output power compared to the standard one. However, recent thermal and laser measurements have shown that the heat transfer out of the heat spreader is still hampered by bottlenecks at the transitions between different parts of the gain chip holder, limiting the power scaling ability. A new chip-holder was designed to overcome these thermal problems. Its design as well as results of AlGaInP VECSELs emitting at 665 nm will be presented.