| 摘要 |
PURPOSE:To obtain excellent oscillation characteristics and modulation characteristics by a simple structural process by making the thickness of the well layer of a quantum well layer in a first region larger than that of a well layer in a second region. CONSTITUTION:A diffraction grating at pitches of 4000Angstrom is formed onto an optical waveguide layer in an active region 21. The active region 21 and an optical modulation region 22 are isolated electrically by a proton injection layer 13. The well-layer thickness Lz of an MQW layer 2 is 100Angstrom and barrier- layer thickness thereof is 100Angstrom in the optical modulation region 22, though the well-layer thickness Lz of the layer 2 is 200Angstrom and barrier-layer thickness thereof is 200Angstrom in the active region 21, and film thickness differs in the regions 21 and 22. When forward DC currents are applied between the electrodes 6-12 in the region 21 at that time, laser oscillation having a wavelength of 1.30mum is acquired. On the other hand, a reverse bias is applied between electrodes 11-12 in the optical modulation region 22, thus allowing optical modulation. |
