| abstract |
An optical integrated circuit device comprises a compound semiconductor substrate 1, a semiconductor laser 2 comprising a compound semiconductor layer, a waveguide 3 comprising a compound semiconductor layer having the same energy band gap as that of the semiconductor laser 2, a semiconductor amplifier 4 comprising a compound semiconductor layer having the same energy band gap as that of the semiconductor laser 2, a common electrode 8 disposed on the rear surface of the substrate 1, a semiconductor laser electrode 6 for conducting current between the electrodes 6,8 so that the current is injected into the laser 2, a waveguide electrode 9 for conducting current between the electrodes 9,8 so that the current is injected into the waveguide 3, and a semiconductor amplifier electrode 7 for conducting current between the electrodes 7,8 so that the current is injected into the amplifier 4. Absorption loss in the waveguide 3 is suppressed by applying a voltage across the common electrode 8 and the waveguide electrode 9 to inject current into the waveguide 3. |