| 摘要 |
PROBLEM TO BE SOLVED: To efficiently amplify C- and L-band waves. SOLUTION: C-band signal light SC and L-band signal light SL are input to an EDF 14 via ports A and B of an optical circulator 10 and WDM optical coupler 12. The optical coupler 12 supplies excitation light from an excitation LD 20 to an EDF 14. The EDF 14, which is excited by the excitation light, amplifies the C-band signal light SC to generate C-band ASE light. A reflector 15 reflects most of the signal light SC and C-band ASE light and passes the remaining light and signal light SL therethrough. The signal light SC is again amplified by the EDF 14 and output from a port C of the circulator 10 via the optical coupler 12 and via the port B of the circulator. Light, transmitted through the reflector 16, is directed into an EDF 22 via an optical isolator 18 and a WDM optical coupler 20, and the optical coupler 20 supplies an EDF 22 with the excitation light from an excitation LD 32. The EDF 22 amplifies the excitation light and the signal light SL from C-band light received from the optical isolator 18. An optical circulator 28 and a C-band reflector 26 combine the amplified signal light SC and signal light SL. |
