LIGHT BEAM DEFLECTOR

PURPOSE:To obtain a high-performance deflector which maintains the variability of beam deflection, and simultaneously compensates coupling loss and carrier loss by enabling the change in a refractive index and the amplification degree of light beam to be controlled independently. CONSTITUTION:On a single conductor type semiconductor substrate 11, there are laminated a conductor type optical guide layer 13, an opposite conductor type spacer layer 14, a single conductor type optical amplifier layer 15 where a band gap is either smaller or equivalent to the optical guide layer, a one conductivity type clad layer 16 by way of a secondary or higher-order diffraction grating 12. Then, electric current is independently injected into the layer 13 and the layer 15 with power sources V1 and V1 where input light is arranged to enter from the end face of the laminated layer while output light is plane-discharged from the surface of the clad layer. The band filing effect of the layer 13 by the injection current of the power source V1 with its plasma effect reduces the refractive index and changes an angle theta of discharge beam from its vertical direction. Furthermore, the gain of the optical amplification layer can be controlled with the injection current based on the power supply V2. It is, therefore, possible to obtain a high-performance light beam deflector which compensates coupling loss and carrier loss by controlling the power sources V1 and V2.