Optical analog-to-digital converter, method of constructing the same, optical signal demodulator, and optical modulator-demodulator

摘要

An optical A/D converter according to the present invention includes an optical splitter that splits an analog input signal light into plurals, a plurality of Mach-Zehnder interferometers to which each of the signal lights split by the optical splitter is input, and plurality of optical/electrical conversion unit that convert each signal lights output from each Mach-Zehnder interferometer into a digital electrical signal, in which each Mach-Zehnder interferometer includes optical intensity-to-phase conversion unit that optically convert intensity of the input signal light into an amount of phase shift and the amount of phase shift differs for each Mach-Zehnder interferometer. Then, it is possible to provide a high speed and low power consuming optical demodulation circuit.

主权项

1. An optical A/D converter, comprising:
an optical splitter that splits an input analog optical signal into a plurality of optical signals; a plurality of Mach-Zehnder interferometers, each of the plurality of optical signals split by the optical splitter being input to the plurality of Mach-Zehnder interferometers; a plurality of optical/electrical conversion units that convert each optical signal output from each of the Mach-Zehnder interferometers into a digital electrical signal, wherein each of the Mach-Zehnder interferometers comprises:
an internal optical splitter that splits an input light into two lights;first and second waveguides connected to the internal optical splitter;a third waveguide to which a light different from a light input to the first and second waveguides is input;an optical modulation region connected to the first, second, and third waveguides; anda coupler/splitter connected to the first and second waveguides, wherein the optical modulation region comprises an optical intensity-to-phase conversion unit that shifts a phase of the light input to the second waveguide according to an intensity of the light input to the third waveguide, wherein one of the optical signal and a local light having a wavelength different from that of the optical signal is input to the first and second waveguides, and another of the optical signal and the local light is input to the third waveguide, wherein the optical modulation region outputs the optical signal and the local light separately, and wherein an amount of a phase shifted by the optical intensity-to-phase conversion unit shift differs for said each of the Mach-Zehnder interferometers.