Optical modulation device

Patent metadata

Field	Value
Publication number	US-9817294-B2
Application number	US-201514748895-A
Country	US
Kind code	B2
Filing date	Jun 24, 2015
Priority date	Dec 27, 2012
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

An optical modulation device configured of a planar optical waveguide, includes: a light incidence unit which allows light to be incident on the planar optical waveguide; a Mach-Zehnder interferometer which includes a first optical splitter section branching the light incident on the light incidence unit, two arm portions guiding the light branched by the first optical splitter section, a phase modulation unit linearly disposed on each of the two arm portions, and a first optical coupler section combining the light guided from the two arm portions; a light launching unit which launches the light combined by the first optical coupler section from the planar optical waveguide; and a traveling-wave electrode which includes an input unit and an output unit, and applies a voltage to the phase modulation unit.

First claim

What is claimed is:

1. An optical modulation device, comprising:
a planar optical waveguide;
a light incidence unit which allows light to be incident on the planar optical waveguide;
a Mach-Zehnder interferometer which comprises a first optical splitter section branching the light incident on the light incidence unit, two arm portions guiding the light branched by the first optical splitter section, a phase modulator comprising a first phase modulation unit linearly disposed on a first one of the two arm portions and a second phase modulation unit disposed on a second one of the two arm portions, and a first optical coupler section combining the light guided from the two arm portions;
a light launching unit which launches the light combined by the first optical coupler section from the planar optical waveguide;
a traveling-wave electrode which comprises an input unit and an output unit, and applies a voltage to the phase modulator; and
a groove portion which is configured to fix an optical fiber,
wherein the planar optical waveguide has an outline comprising a first side and a second side, wherein each of the first side and the second side intersect with an extended line extending in a longitudinal direction of the phase modulator in a plan view,
the input unit is formed on one of the first side and the second side,
the light incidence unit and the light launching unit are positioned in a region different from a region in which the traveling-wave electrode is formed in a plan view, and
a first end of the groove portion is formed on the outline, and at least one of the light incidence unit and the light launching unit is formed on a second end of the groove portion.

2. The optical modulation device according to claim 1 ,
at least one of the light incidence unit and the light launching unit is arranged on a same side, of the first side and the second side, on which the output unit is arranged.

3. The optical modulation device according to claim 2 ,
the light launching unit is arranged on the same side, of the first side and the second side, on which the output unit is arranged.

4. The optical modulation device according to claim 1 ,
wherein an optical waveguide configuring the phase modulator comprises a rib waveguide comprising a rib portion, and a pair of slab portions respectively connected to both sides of the rib portion,
a rectangular waveguide is connected to at least one end of the rib waveguide, and
a transition region in which a width between the pair of slab portions is continuously changed to be optically coupled to the rectangular waveguide, is included in a connection portion between the rib waveguide and the rectangular waveguide.

5. The optical modulation device according to claim 1 ,
wherein a distance between the first phase modulation unit and the first side is identical to a distance between the second phase modulation unit and the first side, and a distance between the first phase modulation unit and the second side is identical to a distance between the second phase modulation unit and the second side, and
the light incidence unit and the light launching unit are positioned in a region between a first line and a second line, wherein:
the first line is parallel with the first side and the second side and intersects a first end portion of the first phase modulation unit of the Mach-Zehnder interferometer and a first end portion of the second phase modulation unit of the Mach-Zehnder interferometer, and
the second line is parallel with the first side and the second side and intersects a second end portion of the first phase modulation unit of the Mach-Zehnder interferometer and a second end portion of the second phase modulation unit of the Mach-Zehnder interferometer.

6. The optical modulation device according to claim 1 ,
wherein the longitudinal direction of the phase modulator has an inclination at an angle of greater than 0° and less than 90° with respect to each of the two sides, and
a distance between the first phase modulation unit and the first side is identical to a distance between the second phase modulation unit and the first side, and a distance between the first phase modulation unit and the second side is identical to a distance between the second phase modulation unit and the second side.

7. The optical modulation device according to claim 1 ,
wherein the longitudinal direction of the phase modulator is perpendicular to the two sides.

8. The optical modulation device according to claim 1 ,
wherein the longitudinal direction of the phase modulator has an inclination at an angle of greater than 0° and less than 90° with respect to each of the two sides.

9. The optical modulation device according to claim 1 ,
wherein a distance between the first phase modulation unit and the first side is identical to a distance between the second phase modulation unit and the first side, and a distance between the first phase modulation unit and the second side is identical to a distance between the second phase modulation unit and the second side.

10. The optical modulation device according to claim 1 ,
wherein the input unit is formed on the first side and the output unit is formed on the second side.

11. The optical modulation device according to claim 1 ,
wherein the traveling-wave electrode is linearly formed from the input unit to the output unit.

12. The optical modulation device according to claim 1 ,
wherein the planar optical waveguide is in a shape of a polygon comprising a plurality of sides, including the first side and the second side, in a plan view, and
the light incidence unit and the light launching unit are each arranged on a side different from the first side and the second side among the plurality of sides.

13. The optical modulation device according to claim 1 ,
wherein the planar optical waveguide is in a shape of a polygon comprising a plurality of sides, including the first side and the second side, in a plan view, and
the light incidence unit and the light launching unit are each arranged on any one of the plurality of sides, and a side on which the light incidence unit is arranged is different from a side on which the light launching unit is arranged.

14. The optical modulation device according to claim 1 ,
wherein the planar optical waveguide is in a shape of a polygon comprising a plurality of sides, including the first side and the second side, in a plan view, and
the light incidence unit and the light launching unit are each arranged on any one of the plurality of sides, and a side on which the light incidence unit is arranged is identical to a side on which the light launching unit is arranged.

15. The optical modulation device according to claim 1 ,
wherein the planar optical waveguide comprises a plurality of Mach-Zehnder interferometers.

16. The optical modulation device according to claim 15 , further comprising:
at least one of a second optical splitter section which branches the light incident from the light incidence unit and launches the light to the plurality of Mach-Zehnder interferometers, and a second optical coupler section which combines the light launched from the plurality of Mach-Zehnder interferometers.

17. The optical modulation device according to claim 15 , further comprising:
a second optical splitter section which branches the light incident from the light incidence unit and launches the light to the plurality of Mach-Zehnder interferometers, and
at least one of a plurality of waveguides connecting the plurality of Mach-Zehnder interferometers to the

Assignees

• Fujikura Ltd

Inventors

• Goi Kazuhiro
• Ishihara Hiroki
• Ogawa Kensuke
• Oda Kenji
• Kusaka Hiroyuki
• Matsumoto Ryokichi
• Uemura Hitoshi

Classifications

• G02F2201/58

  Arrangements comprising a monitoring photodetector · CPC title

• G02B2006/12097

  Ridge, rib or the like · CPC title

• G02F1/218

  using semi-conducting materials · CPC title

• G02F1/025 Primary

  in an optical waveguide structure (G02F1/017, {G02F1/2257} take precedence) · CPC title

• G02B6/29355

  Cascade arrangement of interferometers · CPC title