OPTICAL SEPARATING AND SWITCHING DEVICE FOR WAVELENGTH MULTIPLEX SIGNAL

摘要

PURPOSE:To select wavelength without any deterioration in the intensity of signal light by amplifying or attenuating wavelength multiplex signal light in a rare earth element added optical fiber which is different in amplification degree. CONSTITUTION:An input optical fiber 1 is connected to the incident terminal of an optical branch device 2, whose two projection terminals are connected to one-incidence-terminal sides of optical couplers 5 and 6 through optical fibers 3 and 4 for connection. Then exciting light beams from Nd exciting light sources 15 and 16 are made incident on the other-incidence-terminal sides of the optical couplers 5 and 6 under the control of a control circuit 19. Then the exiting terminals of the optical couplers are connected to one-incidence-terminal sides of optical couplers 9 and 10 through Nd-added optical fibers 7 and 8. Further, exciting light beams from Bgamma exciting light sources 17 and 18 are made incident on the other-incidence-terminal sides of the optical couplers 9 and 10 under the control of the control circuit 19. Then the exiting terminals of the optical couplers 9 and 10 are connected to output optical fibers 13 and 14 through Bgamma-added optical fibers 11 and 12.