Optical branching unit, optical communication system, and optical multiplexing method

摘要

An optical-branching unit enables suppression of deterioration of the transmission characteristic of a survivor signal without executing complex control of constant-power output. Optical-amplification means amplifies and supplies a input optical signal, and when not receiving the optical signal, amplifies and supplies amplified spontaneous emission that the optical-amplification means generates. Detection means detects whether the optical signal is input to the optical-amplification means. When the optical signal is not input to the optical-amplification means, control means sets gain that determines the magnitude of amplification in the optical-amplification means to a predetermined value greater than gain at the time the optical signal is input to the optical-amplification means. Add/drop-multiplexing means receives the output light from the optical-amplification means and other output light and multiplexes an optical signal of a predetermined wavelength in the output light from the optical-amplification means and an optical signal of a specific wavelength in the other output light.

主权项

1. An optical branching unit comprising:
an optical amplification unit that, when an optical signal is received as input, amplifies and supplies the optical signal, or, when said optical signal is not received as input, amplifies and supplies amplified spontaneous emission that the optical amplification unit itself generates; a detection unit that detects whether said optical signal is applied as input to said optical amplification unit; a control unit that, when said detection unit detects that said optical signal is not applied as input to said optical amplification unit, sets gain that determines the magnitude of amplification in said optical amplification unit to a predetermined value that is greater than said gain when said optical signal is applied as input to said optical amplification unit; an add/drop multiplexing unit that receives output light from said optical amplification unit and other output light and that multiplexes an optical signal of a predetermined wavelength that is contained in the output light from said optical amplification unit and an optical signal of a designated wavelength that is contained in said other output; a designated optical amplification unit that, when a designated optical signal is received as input, amplifies that designated optical signal to supply it as said other output light, or, when said designated optical signal is not received as input, amplifies and supplies amplified spontaneous emission, which said designated optical amplification unit itself generates, as said other output light; a designated detection unit that detects whether said designated optical signal is applied as input to said designated optical amplification unit; and a designated control unit that, when said designated detection unit detects that said designated optical signal is not applied as input to said designated optical amplification unit, sets designated gain that determines the magnitude of amplification in said designated optical amplification unit to a designated value that is greater than said designated gain at the time when said designated optical signal is applied as input to said designated optical amplification unit.