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Oscillator strength of optical transitions in InGaAsN/GaAsN/GaAs quantum wells

Mika A, Sek G, Ryczko K, Kozub M, Musial A, Marynski A, Misiewicz J, Langer F, Höfling S, Appel T, Kamp M, Forchel A

Optica Applicata

2013

Vol. 43, nr 1

53--60

Experimental and theoretical considerations and results on the effect of nitrogen incorporation on the oscillator strength of optical transitions in InGaNAs/GaAs quantum wells (QWs) are presented. Therefore, a set of dilute nitride quantum well structures was grown by molecular beam epitaxy. Optical investigation via spectroscopic methods have been performed at various temperatures for both the as-grown samples, and after rapid thermal annealing. The fundamental transition energy and its oscillator strength vs. the QW composition have been systematically investigated. Additionally, the effect of the bandgap discontinuities on the transitions intensity has also been considered. The experimental data have been confronted with the band structure calculations within the effective mass approximation employing a two level repulsion model for the nitrogen-containing structures. The obtained results are crucial for possible future applications employing the quantum well in cavity structures and bringing the practical exploitation of quantum electrodynamics phenomena to the telecommunication spectral range.

Above GaSb barrier in type II quantum well structures for mid-infrared emission detected by Fourier-transformed modulated reflectivity

Motyka M., Janiak F., Ryczko K., Sęk G., Misiewicz J., Bauer A., Weih R., Höfling S., Kamp M., Forchel A.

Opto-Electronics Review

2011

Vol. 19, No. 2

137-139

Modulation spectroscopy in its Fourier-transformed mode has been employed to investigate the optical properties of broken gap 'W'-shaped GaSb/AlSb/InAs/InGaSb/InAs/AlSb/GaSb quantum well structures designed to emit in the mid infrared range of 3-4 µm for applications in laser-based gas sensing. Besides the optical transitions originating from the confined states in the type II quantum wells, a number of spectral features at the energy above the GaSb band gap have been detected. They have been analyzed in a function of InAs and GaSb layer widths and ultimately connected with resonant states in the range of AlSb tunneling barriers.