Patent ID: 7068425

Claim:
A wideband optical fiber amplifier for amplifying and outputting wideband optical signals, the wideband optical signal including C-band optical signals and L-band optical signals, comprising; a first amplification section for amplifying and outputting the wideband optical signals including the C-band optical signals and the L-band optical signals and for outputting amplified spontaneous emissions generated in a process of amplifying the wideband optical signals; a C/L splitter for separating the wideband optical signals amplified by the first amplification section into the C-band optical signals and the L-band optical signals and then outputting separated C-band optical signals and separated L-band optical signals; a second amplification section for amplifying and outputting the separated L-band optical signals; an optical signal coupler for combining the separated C-band optical signals output from the C/L splitter with the separated L-band optical signals amplified by the second amplification section and then outputting the combined optical signals; and an optical circulator having a first port for receiving the wideband optical signals, a second port for causing the wideband optical signals to be output and for causing spontaneous emission generated form the first amplification section to be input, a third port for causing the spontaneous emissions to be provided as pumping lights for the second amplification section and for causing the separated L-band optical signals amplified by the second amplification section to be input and a fourth port for causing the L-band optical signals input into the third port to be output to the optical signal coupler.