OPTICAL COUPLING METHOD FOR BACKWARD EXCITATION AND OPTICAL COUPLER FOR BACKWARD EXCITATION USING THE METHOD

摘要

PROBLEM TO BE SOLVED: To solve many conventional problems that at least a polarized wave combiner, a WDM coupler and excessive optical fibers are necessary in order to input exciting light for posterior excitation in an erbium doped fiber(EDF), an optical coupler is large and expensive, and a loss is large and so on. ;SOLUTION: The above problems are solved by making a WDM coupler function, a polarized wave synthesis function, an isolator function, and further an isolator function for protection of an excitation light source together by one isolator element. Specifically, a single mode fiber(SMF) collimator is arranged at the input side of an isolator element, the SMF collimator and a polarization maintaining fiber(PMF) collimator are arranged at the output side of the isolator element, then exciting light is inputted from the PMF collimator.;COPYRIGHT: (C)2001,JPO