Intersubband absorption in highly photoexcited semiconductor quantum wells |
| |
| Authors: | S. Hanna S. R. Schmidt V. A. Shalygin D. A. Firsov L. E. Vorobjev V. M. Ustinov A. E. Zhukov A. Seilmeier |
| |
| Affiliation: | a Physikalisches Institut, Universität Bayreuth, Universitaetsstr. 30, Bayreuth D-95440, Germany;b St. Petersburg State Polytechnic University, St. Petersburg 195251, Russia;c Ioffe Physico-Technical Institute, St. Petersburg 194021, Russia |
| |
| Abstract: | Transient mid infrared (MIR) absorption spectroscopy is used to investigate transitions between higher electronic subbands in semiconductor quantum well (QW) structures after interband photoexcitation with intense picosecond pulses in the visible spectral range. Our investigation focuses on the e2–e3 intersubband transition in an asymmetric undoped GaAs/AlGaAs QW structure. At an injected nonequilibrium carrier density of 1×1013 cm−2/QW, an e2–e3 absorption band at 99 meV with a spectral width of 5 meV is found. For a higher density studied, 3×1013 cm−2/QW, the band is broadened and blueshifted by 30 meV. Intersubband absorption signals are distinguished from free-carrier absorption signals in the MIR by their characteristic time behavior. |
| |
| Keywords: | Quantum wells High excitation Intersubband transition Free-carrier absorption Time-resolved spectroscopy |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
