Wavelength conversion device and optical transmission system
A wavelength conversion device includes an optical medium that converts a first wavelength-multiplexed light including a plurality of first wavelengths belonging to a first wavelength band to a second wavelength-multiplexed light including a plurality of second wavelengths belonging to a second wavelength band, a first monitor configured to monitor power of the plurality of second wavelengths belonging to the second wavelength band, a storage unit that holds control information for adjusting a conversion characteristic of the optical medium, and a control unit configured to perform control of adjusting the conversion characteristic of the optical medium based on the control information acquired from the storage unit according to a first monitoring result by the first monitor.
1 . A wavelength conversion device comprising:
an optical medium that converts a first wavelength-multiplexed light including a plurality of first wavelengths belonging to a first wavelength band to a second wavelength-multiplexed light including a plurality of second wavelengths belonging to a second wavelength band;
a first monitor that monitors power of the plurality of second wavelengths belonging to the second wavelength band;
a storage that holds control information for adjusting a temperature of the optical medium so as to adjust conversion characteristic of the optical medium; and
a controller that performs control of adjusting the temperature of the optical medium based on the control information acquired from the storage according to a first monitoring result by the first monitor,
wherein the controller resets the control when a decrease amount of a conversion efficiency based on adjustment of the temperature exceeds a deviation of the power of the plurality of second wavelengths belonging to the second wavelength band before the adjustment of the temperature.
2 . The wavelength conversion device according to claim 1 , wherein the controller performs first control of adjusting the temperature of the optical medium according to the control information so as to compensate for a second-order tilt generated in a transmission path through which broadband wavelength-multiplexed light including the plurality of first wavelengths, the plurality of second wavelengths, and a plurality of third wavelengths belonging to a third wavelength band is transmitted.
3 . The wavelength conversion device according to claim 2 , wherein the controller performs second control of adjusting the temperature of the optical medium so as to compensate for variation in zero-dispersion wavelength, and performs the first control after recording the control information in the storage based on a result of the second control.
4 . The wavelength conversion device according to claim 3 , wherein the controller resets the first control when the decrease amount exceeds the deviation.
5 . The wavelength conversion device according to claim 2 ,
wherein the first wavelength band is an S-band,
wherein the second wavelength band is a C-band, and
wherein the third wavelength band is an L-band.
6 . The wavelength conversion device according to claim 1 , wherein the controller performs the control of adjusting the temperature of the optical medium by a heater or a cooler.
7 . The wavelength conversion device according to claim 1 , further comprising:
a pumping light source that outputs a pumping light,
wherein the controller performs the control of adjusting the temperature of the optical medium by adjusting a wavelength of the pumping light input from the pumping light source to the optical medium.
8 . The wavelength conversion device according to claim 1 , wherein the optical medium is a nonlinear optical medium containing PPLN (Periodically Poled Lithium Niobate).
9 . A wavelength conversion device comprising:
an optical medium that converts a first wavelength-multiplexed light including a plurality of first wavelengths belonging to a first wavelength band to a second wavelength-multiplexed light including a plurality of second wavelengths belonging to a second wavelength band;
a first monitor that monitors power of the plurality of second wavelengths belonging to the second wavelength band;
a storage that holds control information for adjusting a conversion characteristic of the optical medium;
a controller that performs control of adjusting the conversion characteristic of the optical medium based on the control information acquired from the storage according to a first monitoring result by the first monitor; and
a second monitor that monitors power of the plurality of first wavelengths belonging to the first wavelength band,
wherein the controller performs the control of adjusting the conversion characteristic of the optical medium based on the control information acquired from the storage according to the first monitoring result and a second monitoring result by the second monitor.
10 . An optical transmission system comprising a receiving-end wavelength conversion device and a transmitting-end wavelength conversion device,
wherein the receiving-end wavelength conversion device includes:
a receiving-end optical amplifier that amplifies a first wavelength-multiplexed light including a plurality of first wavelengths belonging to a first wavelength band;
a first optical medium that converts the first wavelength-multiplexed light after amplification to a second wavelength-multiplexed light including a plurality of second wavelengths belonging to a second wavelength band;
a receiving-end first monitor that monitors power of the plurality of second wavelengths belonging to the second wavelength band;
a first storage that holds first control information for adjusting conversion characteristics of the first optical medium; and
a receiving-end controller that performs control to adjust the conversion characteristics of the first optical medium based on the first control information acquired from the first storage according to a first monitoring result by the receiving-end first monitor, and
wherein the transmitting-end wavelength conversion device includes:
a second optical medium that converts the second wavelength-multiplexed light output from a first transmitter to the first wavelength-multiplexed light;
a transmitting-end first optical amplifier that amplifies the first wavelength-multiplexed light after conversion;
a transmitting-end second optical amplifier that amplifies the second wavelength-multiplexed light output from a second transmitter; and
an optical coupler that combines the second wavelength-multiplexed light output from the transmitting-end second optical amplifier and the first wavelength-multiplexed light output from the transmitting-end first optical amplifier and outputs a resulting light to a transmission line connecting the receiving-end wavelength conversion device and the transmitting-end wavelength conversion device.
11 . The optical transmission system according to claim 10 ,
wherein the transmitting-end wavelength conversion device includes:
a transmitting-end first monitor that monitors power of the plurality of first wavelengths belonging to the first wavelength band;
a second storage that holds second control information for adjusting conversion characteristics of the second optical medium; and
a transmitting-end controller that performs control to adjust the conversion characteristics of the second optical medium based on the second control information acquired from the second storage according to the first monitoring result output from the receiving-end controller and a second monitoring result by the transmitting-end first monitor.
12 . The optical transmission system according to claim 10 ,
wherein the receiving-end wavelength conversion device includes an OSC transmitter that optically transmits the first monitoring result output from the receiving-end controller, and
wherein the transmitting-end wavelength conversion device includes:
a second monitor that monitors power of the plurality of first wavelengths belonging to the first wavelength band;
a second storage that holds second control information for adjusting conversion characteristics of the second optical medium;
an OSC receiver that optically receives the first monitoring result transmitted from the OSC transmitter; and
a transmitting-end controller that performs control to adjust the conversion characteristics of the second optical medium based on the second control information acquired from the second storage according to the first monitoring result received by the OSC receiver and a second monitoring result by the second monitor.
13 . The optical transmission system according to claim 10 ,
wherein the receiving-end wavelength conversion device includes a receiving-end second monitor that monitors power of the plurality of first wavelengths belonging to the first wavelength band,
wherein the receiving-end controller acquires, from the receiving-end second monitor, a second monitoring result by the receiving-end second monitor and outputs the second monitoring result together with the first monitoring result to the transmitting-end wavelength conversion device, and
wherein the transmitting-end wavelength conversion device includes:
a transmitting-end first monitor that monitors power of the plurality of first wavelengths belonging to the first wavelength band; and
a transmitting-end controller that performs control to adjust a slope of the transmitting-end first optical amplifier and control to adjust conversion characteristics of the second optical medium with temperature according to the first monitoring result and the second monitoring result output from the receiving-end controller and a third monitoring result by the transmitting-end first monitor so that a deviation of power of each wavelength of the first wavelength-multiplexed light after passing through the transmission line is reduced.
14 . The optical transmission system according to claim 10 ,
wherein the transmitting-end wavelength conversion device includes:
a first variable optical attenuator that attenuates power of the first wavelength-multiplexed light output from the transmitting-end first optical amplifier;
a second variable optical attenuator that attenuates power of the second wavelength-multiplexed light output from the transmitting-end second optical amplifier;
a transmitting-end first monitor that monitors power of the plurality of first wavelengths belonging to the first wavelength band;
a transmitting-end second monitor that monitors power of the plurality of second wavelengths belonging to the second wavelength band; and
a transmitting-end controller that performs control to adjust respective slopes of the transmitting-end first optical amplifier and the transmitting-end second optical amplifier, control to adjust respective attenuation amounts of the first variable optical attenuator and the second variable optical attenuator, and control to adjust conversion characteristics of the second optical medium with temperature according to a third monitoring result by the transmitting-end first monitor and a fourth monitoring result by the transmitting-end second monitor so that a deviation of power of each wavelength of the first wavelength-multiplexed light before passing through the transmission line is reduced.
15 . The optical transmission system according to claim 10 ,
wherein in the receiving-end wavelength conversion device, the receiving-end controller acquires the first monitoring result for each wavelength band, calculates a linear first signal quality for each wavelength band based on a predetermined first calculation method for calculating a linear signal quality and the first monitoring result, and outputs the linear first signal quality for each wavelength band, which has been calculated, to the transmitting-end wavelength conversion device,
wherein the transmitting-end wavelength conversion device includes:
a transmitting-end first monitor that monitors power of the plurality of first wavelengths belonging to the first wavelength band;
a transmitting-end second monitor that monitors power of the plurality of second wavelengths belonging to the second wavelength band; and
a transmitting-end controller that
calculates a nonlinear second signal quality for each wavelength band based on a predetermined second calculation method for calculating a nonlinear signal quality, a third monitoring result by the transmitting-end first monitor, and a fourth monitoring result by the transmitting-end second monitor,
calculates a third signal quality, which is different from the linear first signal quality and the nonlinear second signal quality, for each wavelength band based on a predetermined third calculation method for calculating a generalized signal quality, the linear first signal quality output from the receiving-end controller, and the nonlinear second signal quality, and
performs control to adjust respective slopes of the transmitting-end first optical amplifier and the transmitting-end second optical amplifier and control to adjust conversion characteristics of the second optical medium with temperature so that the third signal quality is reduced.
16 . The optical transmission system according to claim 10 ,
wherein the transmitting-end wavelength conversion device includes:
a first variable optical attenuator that attenuates power of the first wavelength-multiplexed light output from the transmitting-end first optical amplifier;
a second variable optical attenuator that attenuates power of the second wavelength-multiplexed light output from the transmitting-end second optical amplifier;
a transmitting-end first monitor that monitors power of the plurality of first wavelengths belonging to the first wavelength band;
a transmitting-end second monitor that monitors power of the plurality of second wavelengths belonging to the second wavelength band; and
a transmitting-end controller that
calculates a linear first signal quality and a nonlinear second signal quality for each wavelength band based on a predetermined first calculation method for calculating a linear signal quality, a second calculation method for calculating a nonlinear signal quality, a third monitoring result by the transmitting-end first monitor, and a fourth monitoring result by the transmitting-end second monitor,
calculates a third signal quality, which is different from the linear first signal quality and the nonlinear second signal quality, based on a third calculation method for calculating a generalized signal quality, the linear first signal quality, and the nonlinear second signal quality, and
performs control to adjust respective slopes of the transmitting-end first optical amplifier and the transmitting-end second optical amplifier, control to adjust respective attenuation amounts of the first variable optical attenuator and the second variable optical attenuator, and control to adjust conversion characteristics of the second optical medium with temperature so that the third signal quality is reduced.