Patent ID: 9020353
Filing Date: 2015-04-28
Classification: H04B,H04J

Abstract:
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.