SC-TYPE FIXED OPTICAL ATTENUATOR USING METAL-ION DOPED OPTICAL-FIBER

Seven kinds of SC-type fixed optical attenuator(1) ranging from 3 to 30 dB have been successfully developed using Co2+-ion doped optical fi ber. They have high input power endurance. The main wavelength depende nce in attenuation have been reduced by controlling the Co2+-ion doped area in the fiber core. The fluctuation in attenuation with wavelengt h and PDL degradation caused by the mode coupling were effectively sup pressed in highly attenuative attenuators by using GeO2-doped absorpti on fibers in the outer part of the cladding. The simple structure allo ws us to produce these fixed optical attenuators at a lower cost than conventional ones.