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HL: Fachverband Halbleiterphysik
HL 85: Poster Session II
HL 85.57: Poster
Thursday, March 17, 2011, 18:00–21:00, P4
Gain and reflectance measurements of a 1050nm VECSEL chip — •Sebastian Haupt1,2, Michael Furitsch1, Hans Lindberg1, Ines Pietzonka1, Uwe StrauĂ1, and Gerd Bacher2 — 1Osram Opto Semiconductors GmbH , Leibnitzstrasse 4, 93055 Regensburg — 2WET Universität Duisburg-Essen , 47057 Duisburg
Optically pumped Vertical External Cavity Surface Emitting Lasers (VECSELs) have a wide range of applications due to a combination of output power, high efficiency and a good beam quality in the infrared spectral range. Furthermore the visible spectrum is accessible with intra cavity frequency-doubling.
We will present a method to measure the gain of a 1050 nm VECSEL chip based on a resonant periodic gain (RPG) structure with a reflectance measurement. In the case of a VECSEL the reflectance is determined by the Bragg mirror reflectance and the quantum wells. The reflectance is less than one for carrier densities below transparency and more than one above transparency. In this latter we have an amplification of the light and hence a net gain.
This method has enabled us to measure the gain for a wide spectral, pumping power and temperature range. Additionally we study the influence of different VECSEL Chip anti reflection coatings. The measured gain curves are to be found in good agreement with experiments in laser operation.