Carrier-density dependence of the optical-gain spectra were studied for an undoped T-shaped quantum-wire (T wire) laser by optical pumping at 4 K. The gain appeared at a low excitation power of 3 mW corresponding to the carrier density of about 3 × 105 cm-1 in the T wire. As the carrier density was increased, the peak gain increased, but it reached a maximum value of about 1 × 104 cm-1 at the carrier density of 1 × 106 cm-1 and then decreased hereafter. This peculiar gain evolution dependent on the carrier density was not explained by a simple free-electron model, which suggests significant contributions of the enhanced Coulomb interactions to the optical gain in the T-wire laser.
|ジャーナル||Physica Status Solidi (C) Current Topics in Solid State Physics|
|出版ステータス||Published - 2008 12月 1|
|イベント||34th International Symposium on Compound Semiconductors, ISCS-2007 - Kyoto, Japan|
継続期間: 2007 10月 15 → 2007 10月 18
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