ISSN:
1089-7550
Quelle:
AIP Digital Archive
Thema:
Physik
Notizen:
Data are presented demonstrating phonon-assisted laser operation (77 and 300 K) of photopumped strained-layer AlyGa1−yAs-GaAs-InxGa1−xAs (x∼0.15) quantum-well heterostructures (QWHs) grown using metalorganic chemical vapor deposition. When a cleaved rectangular sample (10–50 μm×100–500 μm) of the QWH, with GaAs substrate removed, is imbedded in In under a sapphire window (for 77-K data), and the In is folded upward along the cleaved edges to provide high edge reflection and high cavity Q, closely spaced end-to-end laser modes (9000 A(ring)) occur along the sample at an energy one LO phonon below the lowest confined-particle transition (ΔE=(h-dash-bar)ωLO≈36 meV), and widely spaced edge-to-edge laser modes occur across the sample on confined-particle transitions. For comparison, the experiment is repeated with rectangular QWH samples clamped on Au with a sapphire window, but with no metal folded onto the sample edges, thus insuring low reflectivity at the cleaved edges (low Q cavity). In the low Q resonator configuration, all of the high-energy modes (transitions on confined-particle states) disappear, and only the low-energy phonon-assisted laser modes are evident. This comparison (high Q versus low Q photoexcitation), as well as the abrupt turn-on of laser operation in a narrow spectral range one phonon (ΔE=(h-dash-bar)ωLO≈36 meV) below the lowest confined-particle transitions, leads to unambiguous identification of phonon-assisted laser operation of a strained-layer AlyGa1−yAs-GaAs-InxGa1−xAs QWH. In addition, bandfilling is demonstrated through the entire well depth of an Lz≈125 A(ring) InxGa1−xAs QW to well above 150 meV into the GaAs QW containing the strained layer.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1063/1.344434
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