| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor light amplifier whose gain is low in wavelength-dependent property. SOLUTION: An active layer contains one of quantum structures which are a quantum dot, a quantum fine wire, and a quantum dash. When a current is injected into the active layer, light propagating inside the active layer is amplified. The active layer is partitioned into a plurality of sections in the direction of propagation, and electrodes are provided to the active layer so as to inject mutually different current into every section. The relation between the density of a current injected into the active layer and the gain coefficients of the active layer, at least, in the two different transition wavelength regions of the quantum structure is graphed. In the graphs, at least, the one section of the active layer has a first current density lower than a current density at a point where two curves intersect each other, and a current is fed to the electrode so as to enable, at least, the other section of the active layer to have a second current density higher than the current density at the point where the two curves intersect each other. COPYRIGHT: (C)2005,JPO&NCIPI |
