Berlin 2008 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 17: Poster I

HL 17.51: Poster

Montag, 25. Februar 2008, 16:30–19:00, Poster D

Optical gain in Ga(NAsP) quantum wells using the variable stripe-length method — •Daniel Franzbach, Christoph Lange, Michael Schwalm, Sangam Chatterjee, Bernadette Kunert, Kerstin Volz, Wolfgang Stolz, and Wolfgang Rühle — Faculty of Physics and Materials Sciences Center, Philipps-Universität Marburg

A series of Ga(NAsP) quantum well samples grown by MOVPE on a GaP substrate with varying concentrations of N and As is measured using the variable stripe-length method.

A Nd:YAG laser is used for excitation. The beam is widened to 4cm, clipped to a rectangular shape and focussed onto the sample. A cylindrical lens allows for exciting a stripe-shaped region, whose length is controlled with two slit apertures. Amplified spontaneous emission is collected from the facet of the sample. By varying the length of the stripe, the gain can be determined.

Both the absorptive regime and spectral regions with optical gain are covered. Different excitation conditions are studied, and gain up to 20/cm is observed. The dependence of the gain maximum on the material composition is determined.