Optical control element
An optical control element having a substrate 1 having an electro-optic effect, an optical waveguide 2 formed on the substrate, and a control electrode 3 that is provided on the substrate and controls the phase of light that propagates through the optical waveguide, in which the control electrode 3 has a plurality of resonant-type electrodes 31 and 32 that are disposed along the optical waveguide 2 and have different resonance frequencies (f 1 and f 2 ), an feeder electrode 30 through which control signals are input and branched signal electrodes that are branched from the feeder electrode are connected to the respective resonant-type electrodes, and the branched signal electrode is configured to match a timing at which the electric control signal is applied to each of the resonant-type electrodes and a timing at which the light that propagates through the optical waveguide passes at the section of each of the resonant-type electrodes.
1. An optical control element comprising:
a substrate having an electro-optic effect;
an optical waveguide formed on the substrate; and
a control electrode that is provided on the substrate and controls phase of light that propagates through the optical waveguide,
wherein the control electrode has a plurality of resonant-type electrodes that are disposed along the optical waveguide and have different resonant frequencies,
a feeder electrode through which control signals are input and branched signal electrodes that are branched from the feeder electrode are connected to the respective resonant-type electrodes, and the branched signal electrode is configured to match a timing at which the electric control signal is applied to each of the resonant-type electrodes and a timing at which the light that propagates through the optical waveguide passes at the section of each of the resonant-type electrodes.
2. The optical control element according to claim 1 ,
wherein the control signal is a rectangular wave, and the resonant frequency is set to an approximately odd harmonic of a fundamental frequency of the rectangular wave.
3. The optical control element according to claim 2 ,
wherein the resonant-type electrodes disposed along the optical waveguide are disposed in a light propagation direction in the order of magnitudes of modulation depths by the respective resonant-type electrodes with respect to the light that propagates through the optical waveguide.
4. The optical control element according to claim 2 ,
wherein the control electrode has a traveling wave-type electrode, and the traveling wave-type electrode is applied with the control signals branched from the feeder electrode.
5. The optical control element according to claim 2 ,
wherein the optical waveguide on which the control electrode is placed is a straight optical waveguide or Mach-Zehnder-type optical waveguide.
6. The optical control element according to claim 1 ,
wherein the resonant frequencies are set to become a specific frequency f and frequencies f±Δf that are different by a predetermined amount Δf from the specific frequency f, and control signals having a single frequency or a plurality of different frequencies are used as the control signal.
7. The optical control element according to claim 6 ,
wherein the resonant-type electrodes disposed along the optical waveguide are disposed in a light propagation direction in the order of magnitudes of modulation depths by the respective resonant-type electrodes with respect to the light that propagates through the optical waveguide.
8. The optical control element according to claim 6 ,
wherein the control electrode has a traveling wave-type electrode, and the traveling wave-type electrode is applied with the control signals branched from the feeder electrode.
9. The optical control element according to claim 6 ,
wherein the optical waveguide on which the control electrode is placed is a straight optical waveguide or Mach-Zehnder-type optical waveguide.
10. The optical control element according to claim 1 ,
wherein the resonant-type electrodes disposed along the optical waveguide are disposed in a light propagation direction in the order of magnitudes of modulation depths by the respective resonant-type electrodes with respect to the light that propagates through the optical waveguide.
11. The optical control element according to claim 10 ,
wherein the control electrode has a traveling wave-type electrode, and the traveling wave-type electrode is applied with the control signals branched from the feeder electrode.
12. The optical control element according to claim 10 ,
wherein the optical waveguide on which the control electrode is placed is a straight optical waveguide or Mach-Zehnder-type optical waveguide.
13. The optical control element according to claim 1 ,
wherein the control electrode has a traveling wave-type electrode, and the traveling wave-type electrode is applied with the control signals branched from the feeder electrode.
14. The optical control element according to claim 13 ,
wherein the optical waveguide on which the control electrode is placed is a straight optical waveguide or Mach-Zehnder-type optical waveguide.
15. The optical control element according to claim 1 ,
wherein the optical waveguide on which the control electrode is placed is a straight optical waveguide or Mach-Zehnder-type optical waveguide.