OPTICAL FIBER ATTENUATOR WITH ATTENUATING DOPANT LIMITED TO A CENTRAL OR PERIPHERAL AREA OF FIBRE CORE

摘要

There is provided an optical attenuator which providesalmost the same degree of attenuance even when the differenceof wavelength of two different kinds of input optical signalsis small. Further, an optical attenuator is realized withdopant concentration in the technically realizable range inincreasing the difference of optical attenuance of twodifferent kinds of input optical signals.