| 摘要 |
PURPOSE:To easily realize an equalizer which compensates up to high-order wavelength dispersion completely by using an optical transmitting medium which has a grating with nearly equal pitch for causing the Bragg reflection of a light transmit signal, and varying the propagation constant of the optical transmitting medium according to the distance in propagation direction of the light transmit signal. CONSTITUTION:A core layer 11 made of glass material which has a higher refractive index than glass material used for a substrate 7 is adhered onto the substrate 7, and the center part of the core layer 11 is projected in a stripe shape in the propagation direction of the light transmit signal. This core layer 11 in said shape confines the incident light transmit signal in both (x) and (y) directions, and a single-mode optical wave guide 10 which is sectioned in an elliptic shape as shown by a broken line is formed. For this purpose, the (y)- directional thickness (t) of said core layer 11 is decreased gradually with the propagation distance in the Z-direction of the propagation of the light transmit signal as shown by a solid line to decrease the propagation constant beta of the optical wave guide 10 gradually. |
