Berlin 2001 – scientific programme
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Q: Quantenoptik
Q 32: Poster: Laser Spectroscopy
Q 32.10: Poster
Friday, April 6, 2001, 12:30–15:00, AT2
Characterization of the nonlinear optical properties of low-temperature-grown GaAs (LT-GaAs) by the z-scan technique with ps and fs pulses — •Herbert Legall1, C. Spitz1, A. Heuer1, R. Menzel1, J. Herfort2, L. Däweritz2, M. Leitner3, and P. Glas3 — 1Universität Potsdam, Physik, Am Neuen Palais 10, 14469 Potsdam — 2Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin — 3Max-Born-Institut, Max-Born-Str. 2a, 12489 Berlin
In recent years, low-temperature-grown GaAs (LT-GaAs) has been the subject of considerable interest because of its strong nonlinear properties combined with short recombination times. Its refractive index changes can be used e.g. for the generation of ultrashort pulses in solid state lasers based on intensity dependent defocussing effects. Thus we investigated the nonlinear optical properties of LT-GaAs at a wavelength of interest for this applications (λ=1060 nm).
The z-scan technique was used to simultaneously determine the refractive index changes and the nonlinear absorption. The measurements were performed for different pulse widths (200 fs and 1.5 ps) in transmission for LT-GaAs layers (grown at 300 oC) bonded on glass, and in reflection for LT-GaAs (grown at 270−300 oC) deposited on a AlAs/GaAs Bragg mirror. The latter case showed enhanced refractive index changes in comparison to the former one.