| 摘要 |
PURPOSE:To make demultiplexing without insertion loss and control of a coupling wavelength possible by providing a gain medium due to p-n junction in a coupling part. CONSTITUTION:A medium is transformed from an absorbing medium to the gain medium with respect to the light having a wavelength lambda0 when a forward current is charged to a p-n junction part 5; and consequently, if the current is kept lower than an oscillation threshold, the light having the wavelength lambda0 is amplified and is coupled to one waveguide in the area 5. The coupled center wavelength lambda0 is controlled because the refractive index is changed by a charged carrier. |
