OPTICAL TRANSMISSION APPARATUS USING EXTENSIVE INPUT DYNAMIC RANGE OPTICAL AMPLIFIER

摘要

PROBLEM TO BE SOLVED: To provide an optical transmission apparatus including an optical amplifier capable of obtaining a large OSNR while keeping an extensive input dynamic range.;SOLUTION: A variable optical attenuator has been conventionally employed to control the optical power level of the input Pin of an optical amplifier module 16. The input optical power level Pin to the module 16 is controlled by substituting a variable photo coupler 35 for a photo coupler for measuring the optical power level of Pin and the variable optical attenuator, and varying the split ratio of the coupler 35. Thus, an optical loss is reduced by a quantity that the optical attenuator is dispensed with, thereby improving the OSNR of the optical amplifier module 16.;COPYRIGHT: (C)2005,JPO&NCIPI