| 摘要 |
PURPOSE:To simultaneously achieve light amplification operation for light in two wavelength bands and to achieve operation for light in both TE mode and in TM mode by including an intermediate barrier layer between a quantum well layer and a barrier layer. CONSTITUTION:In an active layer A, a pair of upper and lower barriers 3a and 3b are constituted by a semiconductor with a inhibited band of higher energy than that of a semiconductor for forming a quantum well layer 1, thus entrapping all electrons and holes in the quantum well layer 1 and intermediate barrier layers 2a and 2b. In the intermediate barrier layers 2a and 2b, the energy levels of the conduction band in a semiconductor constituting them and the valence electron band of a heavy hole are nearly at the same levels as the energy levels of the conduction band in the semiconductor constituting the barrier layers 3a and 3b and the valence electron band of heavy holes and the energy level of the valence electron band of light holes is nearly at the same level as the energy level of the valence electron band of light holes of the quantum well layer 1. |
