Berlin 2005 – scientific programme

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HL: Halbleiterphysik

HL 17: Poster Ib

HL 17.41: Poster

Friday, March 4, 2005, 16:30–19:00, Poster TU F

Characterization of vertical-cavity surface-emitting laser structures by modulation spectroscopy — •C. Karcher, B. Metzger, P.J. Klar, and W. Heimbrodt — Department of Physics and Material Sciences Center, Philipps-University of Marburg, Germany

In recent years, various modulation spectroscopic methods have been successfully applied for characterizing vertical-cavity surface-emitting laser (VCSEL) structures. In particular, photomodulated reflectance (PR) and contactless electroreflectance spectra yield useful information about the coupling between the quantum wells in active region of the device and the cavity. Corresponding line shape models for describing the resonance behavior between quantum well exciton and cavity have been developed. An aspect which has not been addressed is the dynamics of the modulation process in VCSEL structures and its dependence on the resonance between cavity and exciton. These effects can be studied in the frequency domaine by monitoring the quadrature PR signal as a function of modulation frequency. We studied these effects in an InGaAs/GaAs/AlAs VCSEL structure as a function of cavity detuning using modulation frequencies in the range of 1 HZ to about 100 KHz and using various modulation laser wavelengths.