Modulated light signal processing method and apparatus

An optical signal processing method comprising the steps of:

• modulating single-mode light with a first radio wave signal,
• transmitting the optical carrier and optical sideband obtained by means of this modulation,
• inputting the transmitted optical carrier and optical sideband,
• mixing said input optical carrier and optical sideband with a second radio wave of a predetermined frequency,
• optically selecting, from among a frequency-converted optical carrier, a frequency-unconverted optical carrier, a frequency-converted optical sideband and a frequency-unconverted optical sideband obtained by this mixing, a combination of an adjacent optical carrier and optical sideband that have a smaller difference in frequency than the frequency of the first radio wave signal, and
• a step of detecting an electrical signal from the optical signal contained in this selected combination.

An optical signal processing method comprising the steps of:

• generating an optical signal modulated with a first radio wave signal,
• transmitting the optical carrier and optical sideband contained in said modulated optical signal,
• inputting the transmitted optical carrier and optical sideband,
• mixing the input optical carrier and optical sideband with a second radio wave of a predetermined frequency,
• optically selecting, from among a frequency-converted optical carrier, a frequency-unconverted optical carrier, a frequency-converted optical sideband and a frequency-unconverted optical sideband obtained by this mixing, a combination of an adjacent optical carrier wave and optical sideband that have a smaller difference in frequency than the frequency of the first radio wave signal, and
• outputting an electrical signal from the optical signal contained in this selected combination.

An optical signal processing apparatus comprising:

• means of inputting a transmitted optical signal containing an optical carrier and optical sideband,
• means of mixing said input optical signal with a radio wave of a predetermined frequency,
• an optical filter used for optically selecting, from among a frequency-converted optical carrier, a frequency-unconverted optical carrier a frequency-converted optical sideband and a frequency-unconverted optical sideband obtained using this mixing means, a combination of an adjacent optical carrier and optical sideband that have a smaller difference in frequency than the difference in frequency between said input optical carrier and optical sideband, and
• means of detecting an electrical signal from the optical signal contained in the combination selected by this optical filter.

An optical signal processing apparatus comprising:

• a light source that generates single-mode light,
• a modulator that modulates the light from said light source with a first radio wave signal,
• a light path that transmits the optical carrier and optical sideband obtained by means of this modulation,
• means of inputting the transmitted optical signal,
• a mixer that mixes the input optical signal with a second radio wave of a predetermined frequency,
• an optical filter used for optically selecting, from among a frequency-converted optical carrier, a frequency-unconverted optical carrier, a frequency-converted optical sideband and a frequency-unconverted optical sideband obtained by this mixing, a combination of an adjacent optical carrier and optical sideband that have a smaller difference in frequency than the frequency of the first radio wave signal, and
• means of detecting an electrical signal from the optical signal contained in the combination selected by this optical filter.

An optical signal processing apparatus comprising:

• means of generating an optical signal modulated with a first radio wave signal,
• a light path that transmits the optical carrier and optical sideband wave obtained by this modulation,
• means of inputting the transmitted optical signal,
• a mixer that mixes the input optical signal with a second radio wave of a predetermined frequency,
• an optical filter used for optically selecting, from among a frequency-converted optical carrier, a frequency-unconverted optical carrier, a frequency-converted optical sideband and a frequency-unconverted optical sideband obtained by this mixing, a combination of an adjacent optical carrier and optical sideband that have a smaller difference in frequency than the frequency of the first radio wave signal, and
• means of detecting an electrical signal from the optical signal contained in the combination selected by this optical filter.