US 11,838,103 B2
Wavelength conversion device and transmission system
Tomoaki Watanabe, Kawasaki (JP); and Yoshinobu Matsukawa, Kawasaki (JP)
Assigned to FUJITSU LIMITED, Kawasaki (JP)
Filed by FUJITSU LIMITED, Kawasaki (JP)
Filed on May 18, 2022, as Appl. No. 17/747,493.
Claims priority of application No. 2021-121220 (JP), filed on Jul. 26, 2021.
Prior Publication US 2023/0024263 A1, Jan. 26, 2023
Int. Cl. H04J 14/02 (2006.01); H04B 10/50 (2013.01); H04B 10/61 (2013.01); H04B 10/079 (2013.01); H04B 10/572 (2013.01)
CPC H04J 14/0221 (2013.01) [H04B 10/07955 (2013.01); H04B 10/506 (2013.01); H04B 10/572 (2013.01); H04B 10/616 (2013.01); H04J 14/021 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A wavelength conversion device comprising:
a first demultiplexing circuit configured to receive transmission signal light in which first wavelength division multiplexing signal light and second wavelength division multiplexing signal light that have different wavelength bands in which a plurality of rays of main signal light is wavelength-multiplexed are combined with supervisory control signal light that relates to supervisory control of the first wavelength division multiplexing signal light and the second wavelength division multiplexing signal light from a transmission line and that demultiplexes the supervisory control signal light from the transmission signal light;
a first power detection circuit configured to detect input power of the supervisory control signal light;
a second demultiplexing circuit configured to demultiplex each of the first wavelength division multiplexing signal light and the second wavelength division multiplexing signal light from the transmission signal light;
a wavelength conversion circuit configured to convert at least one of the wavelength bands of the first wavelength division multiplexing signal light and the second wavelength division multiplexing signal light into another wavelength band;
a photoelectric conversion circuit configured to convert the supervisory control signal light into an electrical signal;
an acquisition circuit configured to acquire a first information signal and a second information signal that contain supervisory control information of the first wavelength division multiplexing signal light and the second wavelength division multiplexing signal light, respectively, from the electrical signal;
a first signal conversion circuit configured to convert the first information signal into first information signal light;
a second signal conversion circuit configured to convert the second information signal into second information signal light;
a first variable optical attenuator circuit configured to attenuate the first information signal light; attenuate the second information signal light;
a first combining circuit configured to combine the first information signal light attenuated by the first variable optical attenuator and the first wavelength division multiplexing signal light, and outputs the combined first information signal light and first wavelength division multiplexing signal light to a receiving device;
a second combining circuit configured to combine the second information signal light attenuated by the second variable optical attenuator and the second wavelength division multiplexing signal light, and outputs the combined second information signal light and second wavelength division multiplexing signal light to another receiving device; and
a setting circuit configured to calculate a power loss of the supervisory control signal light within the transmission line from the input power of the supervisory control signal light, and sets an attenuation amount based on the power loss of the supervisory control signal light in each of the first variable optical attenuator and the second variable optical attenuator.