Analog-digital conversion method and analog-digital converter
An analog-digital conversion method according to the present invention is a method for converting an optical analog signal into an electrical digital signal, the method including: performing at least one of affine transformation with first reference light and homodyne detection with a detection axis of second reference light on the optical analog signal; converting the optical analog signal subject to transformation or detection into an electrical analog signal by photoelectric conversion; and converting the electrical analog signal into an electrical digital signal by thresholding.
1 . An analog-digital conversion method, the method comprising:
performing first processing on an optical analog signal to obtain a processed optical analog signal, the first processing including affine transformation with first reference light or homodyne detection with a detection axis of second reference light;
converting the processed optical analog signal into an electrical analog signal by photoelectric conversion; and
performing thresholding on the electrical analog signal to convert the electrical analog signal into an electrical digital signal, wherein,
the first processing includes performing the homodyne detection by varying a phase of the second reference light, and
the first processing includes performing the affine transformation by varying an amplitude of the first reference light and the homodyne detection with two phases having a phase difference of π/2 therebetween.
2 . The analog-digital conversion method according to claim 1 wherein:
the first processing includes performing the affine transformation by varying an amplitude of the first reference light.
3 . The analog-digital conversion method according to claim 1 wherein
the second reference light is subject to time variation.
4 . The analog-digital conversion method according to claim 1 , wherein
the first processing includes performing the affine transformation, and
the first reference light is subject to time variation.
5 . The analog-digital conversion method according to claim 1 , wherein
the first processing includes performing the homodyne detection, and
the second reference light is subject to time variation.
6 . The analog-digital conversion method according to claim 1 , wherein,
the first processing includes performing the affine transformation by varying an amplitude of the first reference light.
7 . The analog-digital conversion method according to claim 6 , wherein
the first reference light is subject to time variation.
8 . The analog-digital conversion method according to claim 6 , wherein
the first processing includes performing the homodyne detection with two phases having a phase difference of π/2 therebetween.
9 . The analog-digital conversion method according to claim 8 , wherein
the first reference light or the second reference light is subject to time variation.
10 . The analog-digital conversion method according to claim 1 , wherein
the first reference light or the second reference light is subject to time variation.
11 . An analog-digital converter, comprising:
a first reference light generation circuit configured to generate first reference light;
a computing circuit configured to perform first processing on an optical analog signal, wherein the first processing comprises affine transformation with the first reference light or homodyne detection with a detection axis of second reference light; and
a conversion circuit configured to perform thresholding on the optical analog signal to convert the optical analog signal into an electrical digital signal, wherein,
the first processing includes performing the homodyne detection by varying a phase of the second reference light, and
the first processing includes performing the affine transformation by varying an amplitude of the first reference light and the homodyne detection with two phases having a phase difference of π/2 therebetween.
12 . The analog-digital converter according to claim 11 , further comprising:
a first reference light generation circuit configured to generate first reference light; and
a computing circuit configured to perform affine transformation on the optical analog signal with the first reference light.
13 . An analog-digital conversion method, the method comprising:
performing first processing on an optical analog signal to obtain a processed optical analog signal, the first processing including affine transformation with first reference light or homodyne detection with a detection axis of second reference light;
converting the processed optical analog signal into an electrical analog signal by photoelectric conversion; and
performing thresholding on the electrical analog signal to convert the electrical analog signal into an electrical digital signal,
wherein,
the first processing includes performing the affine transformation by varying an amplitude of the first reference light, and
the first processing includes performing the homodyne detection with two phases having a phase difference of π/2 therebetween.
14 . An analog-digital converter, comprising:
a first reference light generation circuit configured to generate first reference light;
a computing circuit configured to perform first processing on an optical analog signal, wherein the first processing comprises affine transformation with the first reference light; and
a conversion circuit configured to perform thresholding on the optical analog signal to convert the optical analog signal into an electrical digital signal,
wherein,
the first processing includes performing the affine transformation by varying an amplitude of the first reference light, and
the first processing includes performing homodyne detection with two phases having a phase difference of π/2 therebetween.