Optical modulator

Abstract

An optical modulator (100) comprises an optical waveguide (1A), a first electrode (2A), and a second electrode (3). The first electrode (2A) is disposed on one side of the optical modulator (100) in a height direction (HD) with respect to the optical waveguide (1A). The first electrode (2A) has one end (21Aa) and the other end (22Aa) overlapping the optical waveguide (1A) when viewed in the height direction (HD). The second electrode (3) is disposed on the other side in the height direction (HD) with respect to the optical waveguide (1A), and applies an electric field to the optical waveguide (1A) together with the first electrode (2A). When viewed in the height direction (HD), the length of the first electrode (2A) is different from the length, of the optical waveguide (1A), from the position of the one end (21Aa) to the position of the other end (22Aa) of the first electrode (2A).

Claims

1. It is an optical modulator, Two optical waveguides having an electro-optic effect and connected to each other at both ends, A first electrode provided corresponding to each of the optical waveguides, positioned on one side of the optical modulator in the height direction with respect to the optical waveguide, having at least one end and the other end that overlap with the optical waveguide when viewed along the height direction, and extending from the one end to the other end, A second electrode provided corresponding to each of the optical waveguides, the second electrode being positioned on the other side in the height direction relative to the optical waveguide, forming a potential difference with the first electrode and applying an electric field to the optical waveguide together with the first electrode, Viewed along the height direction, the length of the first electrode is different from the length of the optical waveguide from the position of one end to the position of the other end. The optical waveguide includes two waveguide body sections and a waveguide bending section that connects one end of the two waveguide body sections. The first electrode includes two electrode body portions that overlap with the two waveguide body portions when viewed along the height direction, and an electrode bending portion that connects one end of the two electrode body portions and is positioned inside or outside the waveguide bending portion when viewed along the height direction. The length of the electrode bending portion differs from the length of the waveguide bending portion. An optical modulator in which, when viewed along the height direction, a portion of the electrode bending portion is separated from the waveguide bending portion, the first electrode overlaps only with the corresponding optical waveguide of the two optical waveguides, and the second electrode overlaps with the first electrode.

2. The optical modulator according to claim 1, An optical modulator in which, when viewed along the aforementioned height direction, the lengths between the two ends of the optical waveguides are equal to each other.

3. The optical modulator according to claim 1, An optical modulator in which the effective refractive index of the electrical signal passing between the first electrode and the second electrode is smaller than the effective refractive index of the light wave passing through the optical waveguide.

4. The optical modulator according to claim 3, An optical modulator in which the length of the first electrode is greater than the length of the optical waveguide.

5. The optical modulator according to claim 1, The first electrode is an optical modulator including a meandering portion.

6. The optical modulator according to claim 1, An optical modulator in which the effective refractive index of the electrical signal passing between the first electrode and the second electrode is greater than the effective refractive index of the light wave passing through the optical waveguide.

7. The optical modulator according to claim 6, An optical modulator in which the length of the optical waveguide is greater than the length of the first electrode.

8. The optical modulator according to claim 1, The optical waveguide includes a meandering section, and is an optical modulator.

9. An optical modulator according to any one of claims 1 to 8, further, The optical modulator has an input port on the end face along the height direction for inputting light into the optical waveguide, An optical modulator comprising an output port disposed on the end face for outputting light from the optical waveguide.

10. It is an optical modulator, A first optical waveguide having an electro-optic effect, comprising two first waveguide bodies and a first waveguide bending portion connecting one end of the two first waveguide bodies, A second optical waveguide having an electro-optic effect, comprising two second waveguide body portions disposed between two first waveguide body portions, and a second waveguide bending portion that connects one end of the two second waveguide body portions and is disposed between the two second waveguide body portions and the first waveguide bending portion, A first electrode for the first optical waveguide is positioned on one side of the optical modulator in the height direction relative to the first optical waveguide, and has at least one end and the other end that overlap with the first optical waveguide when viewed along the height direction, and extends from the one end to the other end. A first electrode for the second optical waveguide is positioned on one side of the second optical waveguide in the height direction, and has at least one end and the other end that overlap with the second optical waveguide when viewed along the height direction, and extends from the one end to the other end. The system comprises a first optical waveguide and a second optical waveguide, which are positioned on the other side in the height direction, and which form a potential difference with the first electrode for the first optical waveguide and apply an electric field to the first optical waveguide together with the first electrode for the first optical waveguide, and which form a potential difference with the first electrode for the second optical waveguide and apply an electric field to the second optical waveguide together with the first electrode for the second optical waveguide, Looking along the aforementioned height direction, The first electrode for the first optical waveguide is, The two first waveguide body portions and the two first waveguide side electrode body portions that overlap each other, The first waveguide side electrode bending portion connects one end of the two first waveguide side electrode main portions and is positioned outside the first waveguide bending portion, The first electrode for the second optical waveguide is, Two second waveguide side electrode body parts overlapping the two second waveguide body parts, The second waveguide side electrode bending portion connects one end of the two second waveguide side electrode main portions and is positioned inside the second waveguide bending portion or between the first waveguide bending portion and the second waveguide bending portion, An optical modulator in which, when viewed along the height direction, a part of the first waveguide-side electrode bend is separated from the first waveguide bend, a part of the second waveguide-side electrode bend is separated from the second waveguide bend, the first electrode for the first optical waveguide overlaps only with the first optical waveguide of the two optical waveguides, the first electrode for the second optical waveguide overlaps only with the second optical waveguide of the two optical waveguides, and the second electrode overlaps with the first electrode for the first optical waveguide and the first electrode for the second optical waveguide.

11. The optical modulator according to claim 10, The first waveguide-side electrode bending portion is provided on the outside of the first waveguide bending portion, The second waveguide-side electrode bending portion is an optical modulator provided inside the second waveguide bending portion.

12. An optical modulator according to claim 10 or 11, An optical modulator in which, when viewed along the height direction, the second electrode overlaps with the two first waveguide body portions and the two second waveguide body portions, but does not overlap with the first waveguide bending portion and the second waveguide bending portion.

13. An optical modulator according to claim 10 or 11, The other end of one of the two first waveguide bodies is connected to the other end of the second waveguide body that is adjacent to the first waveguide body of the two second waveguide bodies. An optical modulator in which the other end of the second waveguide body of the other of the two first waveguide body parts is connected to the other end of the other second waveguide body of the two second waveguide body parts.

14. The optical modulator according to claim 13, An optical modulator in which the length between the two ends of the first optical waveguide connected to the second optical waveguide is the same as the length between the two ends of the second optical waveguide connected to the first optical waveguide.

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