| 摘要 |
PURPOSE:To eliminate polarization dependency and to reduce the influence of delay dispersion by insertion to an optional place of an optical fiber transmission part by distributing a light signal to a 1st and a 2nd system and coupling the signal of the 1st system side with the light signal of the 2nd system side while delaying the light signal by components through delay optical waveguides on the 1st system side. CONSTITUTION:An intermediate part 3 which is connected between input/output parts 1 and 2 is constituted by repeatedly connecting >=1 unit optical circuits 311-31n in series. The individual unit optical circuits 311-311n are of the same constitution and consist of 1st and 2nd delay optical waveguides (a) and (b) interposed in the system A side respectively and a 3dB directional coupler (c) where the 1st and 2nd delay optical waveguides (a) and (b) are connected in series on the system A side and both ends on the system B side are connected to the system B as a precedent stage. The 1st and 2nd delay optical waveguides (a) and (b) are increased or decreased by 1/2-1/4 time as long as constant length L according to target transmission band width. |
