Dispersion measuring device, pulse light source, dispersion measuring method, and dispersion compensating method

2:

• A dispersion measurement apparatus comprising:
• a pulse forming unit configured to form a light pulse train including a plurality of second light pulses having time differences and center wavelengths different from each other from a first light pulse output from a light source;
• a correlation optical system configured to receive the light pulse train output from the pulse forming unit and passed through a measurement object and output correlation light including a cross-correlation or an autocorrelation of the light pulse train;
• a photodetector configured to detect a temporal waveform of the correlation light;
• and
• a processor configured to estimate a wavelength dispersion amount of the measurement object based on a feature value of the temporal waveform.

5:

• The dispersion measurement apparatus according to claim 4, wherein
• the spatial light modulator is a polarization dependent type spatial light modulator having a modulation function in a first polarization direction,
• the pulse forming unit configured to input the first light pulse including a component of the first polarization direction and a component of a second polarization direction orthogonal to the first polarization direction,
• the component of the first polarization direction in the first light pulse is modulated by the spatial light modulator and output from the pulse forming unit as the light pulse train,
• the component of the second polarization direction in the first light pulse is output from the pulse forming unit without being modulated by the spatial light modulator, and
• the correlation optical system is configured to generate the correlation light including the cross-correlation of the light pulse train from the component of the first polarization direction and the component of the second polarization direction.

7:

• The dispersion measurement apparatus according to claim 1, further comprising:
• an optical branching component configured to branch the light pulse train into two beams;
• and
• a delay optical system configured to provide a time difference between one light pulse train and the other light pulse train branched by the optical branching component, wherein
• the correlation optical system is configured to generate the correlation light including the autocorrelation from the time-delayed one light pulse train and the other light pulse train.

9:

• A pulsed light source comprising:
• the dispersion measurement apparatus according to claim 1;
• and
• a pulse forming apparatus configured to compensate for the wavelength dispersion amount obtained by the dispersion measurement apparatus for a light pulse input to or output from the measurement object.

11:

• A dispersion measurement method comprising:
• performing a pulse forming of forming a light pulse train including a plurality of second light pulses having time differences and center wavelengths different from each other from a first light pulse output from a measurement object;
• performing a correlation light generation of generating correlation light including a cross-correlation or an autocorrelation of the light pulse train;
• performing a detection of detecting a temporal waveform of the correlation light;
• and
• performing an operation of estimating a wavelength dispersion amount of the measurement object based on a feature value of the temporal waveform.

12:

• A dispersion measurement method comprising:
• performing a pulse forming of forming a light pulse train including a plurality of second light pulses having time differences and center wavelengths different from each other from a first light pulse output from a light source;
• performing a correlation light generation of generating correlation light including a cross-correlation or an autocorrelation of the light pulse train output from the pulse forming and passed through a measurement object;
• performing a detection of detecting a temporal waveform of the correlation light;
• and
• performing an operation of estimating a wavelength dispersion amount of the measurement object based on a feature value of the temporal waveform.

15:

• The dispersion measurement method according to claim 14, wherein
• the spatial light modulator is a polarization dependent type spatial light modulator having a modulation function in a first polarization direction,
• in the pulse forming, the first light pulse including a component of the first polarization direction and a component of a second polarization direction orthogonal to the first polarization direction is input, the component of the first polarization direction in the first light pulse is modulated by the spatial light modulator to be the light pulse train, and the component of the second polarization direction in the first light pulse is output without being modulated by the spatial light modulator, and
• in the correlation light generation, the correlation light including the cross-correlation of the light pulse train is generated from the component of the first polarization direction and the component of the second polarization direction.

19:

• A dispersion compensation method comprising:
• estimating the wavelength dispersion amount of the measurement object by using the dispersion measurement method according to claim 11;
• and
• performing pulse forming of compensating for the wavelength dispersion amount for a light pulse input to or output from the measurement object.

22:

• The dispersion measurement apparatus according to claim 21, wherein
• the spatial light modulator is a polarization dependent type spatial light modulator having a modulation function in a first polarization direction,
• the pulse forming unit is configured to input the first light pulse including a component of the first polarization direction and a component of a second polarization direction orthogonal to the first polarization direction,
• the component of the first polarization direction in the first light pulse is modulated by the spatial light modulator and output from the pulse forming unit as the light pulse train,
• the component of the second polarization direction in the first light pulse is output from the pulse forming unit without being modulated by the spatial light modulator, and
• the correlation optical system is configured to generate the correlation light including the cross-correlation of the light pulse train from the component of the first polarization direction and the component of the second polarization direction.

24:

• The dispersion measurement apparatus according to claim 2, further comprising:
• an optical branching component configured to branch the light pulse train into two beams;
• and
• a delay optical system configured to provide a time difference between one light pulse train and the other light pulse train branched by the optical branching component, wherein
• the correlation optical system is configured to generate the correlation light including the autocorrelation from the time-delayed one light pulse train and the other light pulse train.

26:

• A pulsed light source comprising:
• the dispersion measurement apparatus according to claim 2;
• and
• a pulse forming apparatus configured to compensate for the wavelength dispersion amount obtained by the dispersion measurement apparatus for a light pulse input to or output from the measurement object.

30:

• The dispersion measurement method according to claim 29, wherein
• the spatial light modulator is a polarization dependent type spatial light modulator having a modulation function in a first polarization direction,
• in the pulse forming, the first light pulse including a component of the first polarization direction and a component of a second polarization direction orthogonal to the first polarization direction is input, the component of the first polarization direction in the first light pulse is modulated by the spatial light modulator to be the light pulse train, and the component of the second polarization direction in the first light pulse is output without being modulated by the spatial light modulator, and
• in the correlation light generation, the correlation light including the cross-correlation of the light pulse train is generated from the component of the first polarization direction and the component of the second polarization direction.

34:

• A dispersion compensation method comprising:
• estimating the wavelength dispersion amount of the measurement object by using the dispersion measurement method according to claim 12;
• and
• performing pulse forming of compensating for the wavelength dispersion amount for a light pulse input to or output from the measurement object.