Optical modulator and optical signal and electric wave signal converter using same

An optical modulation apparatus comprising:

• an optical signal input section;
• an optical path that propagates the optical signals;
• a branching portion that divides said optical path into a plurality of optical paths;
• an optical modulator that phase modulates said optical signals in at least one of said plurality of optical paths;
• a wavelength selective optical filter that selectively reflects and selectively transmits said optical signals, said filter having a reflection center a distance L from an optical modulating electrode feeding point of said optical modulator, wherein L satisfies (N−¼)(c/f)/(2n)<L<(N+¼)(c/f)/(2n), c is a speed of light, n is a refractive index of an optical waveguide path, f is a frequency of a received high-frequency radio signal, and N is a natural number;
• a structure for combining at said branching portion signals, into which an optical signal input from said input section is divided at said branching portion, and which are phase-modulated by said optical modulator, reflected by said optical filter back alone said optical path and again phase-modulated by said optical modulator, and outputting a combined signal from said input section as an intensity-modulated optical signal.

An optical modulation apparatus comprising:

• an optical signal input section;
• an optical path that propagates the optical signals;
• a branching portion that divides said optical path into a plurality of optical paths;
• an optical modulator that phase modulates said optical signals in at least one of said plurality of optical paths;
• a wavelength selective optical filter that selectively reflects and selectively transmits said optical signals characteristics, said filter having a reflection center a distance L from a center of said optical modulator, wherein L satisfies (N−¼)(c/f)/(2n)<L<(N+¼)(c/f)/(2n), c is a speed of light, n is a refractive index of an optical waveguide path, f is a frequency of a received high-frequency radio signal, and N is a natural number;
• an output section that outputs an optical signal transmitted by said optical filter;
• and
• a structure for combining at said branching portion signals, into which an optical signal input from said input section is divided at said branching portion, and which are phase-modulated by said optical modulator, reflected by said optical filter back alone said optical path and again phase-modulated by said optical modulator, and outputting a combined signal from said input section as an intensity-modulated optical signal.

An optical modulation apparatus comprising:

• an optical signal input section;
• an optical path that propagates the optical signals;
• a branching portion that divides said optical path into a plurality of optical path;
• an optical modulator that phase modulates said optical signals in at least one of said plurality of optical paths;
• a wavelength selective optical filter that selectively reflects and selectively transmits said optical signals, said filter having a reflection center a distance L from an optical modulating electrode feeding point of said optical modulator, wherein L satisfies (N−¼)(c/f)/(2n)<L<(N+¼)(c/f)/(2n), c is a speed of light, n is a refractive index of an optical waveguide path, f is a frequency of a received high-frequency radio signal, and N is a natural number;
• an output section that outputs an optical signal transmitted by said optical the filter;
• and
• a structure for combining at said branching portion signals, into which an optical signal input from said input section is divided at said branching portion, and which are phase-modulated by said optical modulator, reflected by said optical filter back alone said optical path and again phase-modulated by said optical modulator, and outputting a combined signal from said input section as an intensity-modulated optical signal.