2004/06/30 by F. T. Vasko, A. Hernández-Cabrera, A. Hernandez-Cabrera +1 · 3 citations
Chemistry · Engineering · Physics and Astronomy · #Absorption (acoustics) #Atomic physics #Cascade #Chemistry #Condensed matter physics #Electron #Excitation #Ground state #Laser #Optics #Optoelectronics #Phonon #Physics #Semiconductor Quantum Structures and Devices #Spectroscopy and Laser Applications #Stimulated emission #Terahertz radiation #Terahertz technology and applications #Ultrafast laser spectroscopy #Ultrashort pulse #cond-mat.mtrl-sci #cond-mat.other
paper · pdf · doi:10.1103/physrevb.71.245325
published in Physical Review B 71(24) (American Physical Society) · 5 pages, 5 figures, brief report
arxiv created 2005/01/25 · openalex publication_date 2005/06/27 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We have studied the transient evolution of electrons distributed over two levels in a wide quantum well, with the two levels below the optical phonon energy, after an ultrafast interband excitation and cascade emission of optical phonons. If electrons are distributed near the top of the passive region, a temporal negative absorption appears to be dominant in the intersubband response. This is due to the effective broadening of the upper level state under the optical phonon emission. We have then considered the amplification of the ground mode in a THz waveguide with a multiquantum well placed at the center of the cavity. A huge increase of the probe signal is obtained, which permits the temporal stimulated emission regime of the photoexcited electrons in the THz spectral region.