Measurement system and measurement method

A measurement system comprising:

• a wavelength converter configured with a reception unit that coherently detects an input optical signal having a first wavelength and outputting a plurality of analog signals associated to a plurality of phases included in the input optical signal having the first wavelength and a transmission unit that multiplexes a plurality of optical signals and outputting the optical signals, the transmission unit including a driver that outputs a plurality of modulation signals according to the plurality of analog signals and a plurality of modulators that modulate light having a second wavelength different from the first wavelength to the plurality of optical signals associated to the plurality of phases according to the plurality of modulation signals;
• a light source that outputs a first optical signal having the first wavelength to the reception unit;
• a controller that controls the wavelength converter in a state in which the first optical signal is output to the reception unit, so that one specific modulator among the plurality of modulators outputs an optical signal associated to one phase, the optical signal obtained by modulating the light having the second wavelength, the modulators other than the specific modulator do not output optical signals associated to phases other than the one phase, and the specific modulator is sequentially switched among the plurality of modulators;
• and
• a measurement unit that receives a second optical signal output from the transmission unit in a state in which the first optical signal is output to the reception unit, acquiring waveforms of optical signals associated to the plurality of phases selectively included in the second optical signal in response to the switching of the specific modulator, and measuring skew occurring in the optical signals associated to the plurality of phases based on intensities of the acquired waveforms of the optical signals associated to the plurality of phases.

A measurement method comprising:

• outputting a first optical signal having a first wavelength to a reception unit of a wavelength converter configured with the reception unit that coherently detects an input optical signal having the first wavelength and outputting a plurality of analog signals associated to a plurality of phases included in the input optical signal having the first wavelength and a transmission unit that multiplexes a plurality of optical signals and outputting the optical signals, the transmission unit including a driver that outputs a plurality of modulation signals according to the plurality of analog signals and a plurality of modulators that modulate light having a second wavelength different from the first wavelength to the plurality of optical signals associated to the plurality of phases according to the plurality of modulation signals;
• controlling the wavelength converter in a state in which the first optical signal is output to the reception unit, so that one specific modulator among the plurality of modulators outputs an optical signal associated to one phase, the optical signal obtained by modulating the light having the second wavelength, the modulators other than the specific modulator do not output optical signals associated to phases other than the one phase, and the specific modulator is sequentially switched among the plurality of modulators;
• and
• receiving a second optical signal output from the transmission unit in a state in which the first optical signal is output to the reception unit, acquiring waveforms of optical signals associated to the plurality of phases selectively included in the second optical signal in response to the switching of the specific modulator, and measuring skew occurring in the optical signals associated to the plurality of phases based on intensities of the acquired waveforms of the optical signals associated to the plurality of phases.