| 摘要 |
PURPOSE:To improve low-loss characteristics and to eliminate wavelength dependency by injecting carriers in a part of a waveguide layer through the low- resistance area of a clad layer with a voltage applied between 1st and 2nd electrodes. CONSTITUTION:This semiconductor optical switch is equipped with a ridge type waveguide layer 6 which is formed on the other surface of a semiconductor substrate 2 and has a smaller forbidden band than the semiconductor substrate 2 and low carrier density, the clad layer 8 of a 2nd conduction type which is formed on the ridge part of the waveguide layer 6 and has a larger forbidden band than the waveguide layer 6 and high carrier density, a low-resistance area 10 which is formed at a part of the clad layer 8, and a 2nd electrode 18 which is formed on the clad layer 8. Then carriers are injected in a part of the waveguide layer 6 through the low-resistance area 10 of the clad layer 8 with the voltage applied between the 1st electrode 20 and 2nd electrode 18. Consequently, the semiconductor optical switch which performs optical switching with a high quenching ratio and has superior low-loss characteristics and no wavelength dependency is formed at high yield. |
