| 摘要 |
PURPOSE: To constitute a system for emitting light polarized into TE mode without requiring any polarizer while enhancing the degree of polarization of TE/TM significantly as compared with a conventional element. CONSTITUTION: The semiconductor optical element has an active waveguide partially constituted of a strained quantum well structure including a compression type strained quantum well layer. A window structure is formed at one end of the waveguide. The material is designed to satisfy the relationships; E(a)hh<E(w)hh, E(a)hh<E(w) lh<=E(W)lh, where E(w)hh is the band gap between the conduction band 9 of a material composing the window structure and a heavy hole band 10, E(w) lh is the band gap between the conduction band 9 and a light hole band 11, E(a)hh is the band gap between the quantized conduction band 2 of a compression type strain quantum well layer and a heavy hole band 4, and E(a)lh is the band gap between the conduction band 2 and a light hole band 4. Consequently, the window structure region absorbs only the TM mode light. |
