Optical waveguide element module

Patent metadata

Field	Value
Publication number	US-10025121-B2
Application number	US-201515129857-A
Country	US
Kind code	B2
Filing date	Mar 27, 2015
Priority date	Mar 28, 2014
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

An optical waveguide element module decreases discontinuity of electrical connection between an optical waveguide element and a relay substrate, without wire-bonding using long wires. An edge shape L of the signal electrode side of the ground electrode is surrounded by two shapes (L1, L2). Shape L1 is obtained by connecting an input end of the control electrode to a location where a space between the ground electrodes becomes W2. Shape L2 is such that an impedance change of the control electrode from the input end to the location at which the space between the ground electrodes becomes W2 is constant or continuously changes. A space between grounding wires connecting the ground electrodes of the element and ground lines of the relay substrate is larger than a space between the ground electrodes. In an embodiment, a terminal substrate and an output end of the control electrode are connected.

First claim

The invention claimed is:

1. An optical waveguide element module comprising:
an optical waveguide element including a substrate having an electro-optic effect, an optical waveguide formed in the substrate, and a control electrode for controlling light waves that propagate through the optical waveguide; and
a relay substrate which is provided outside the optical waveguide element and has a wire electrically connected to an input end of the control electrode,
the optical waveguide element and the relay substrate being housed in a case,
wherein the control electrode is formed on the substrate of the optical waveguide element, and is constituted of a signal electrode and ground electrodes which put the signal electrode therebetween,
the wire of the relay substrate is constituted of a signal line and ground lines which put the signal line therebetween,
a width of the signal electrode at the input end is smaller than a width of the signal line at an output end of the wire,
in the control electrode of the optical waveguide element, a space W 2 between the ground electrodes at a portion away from the input end is narrower than a space W 1 between the ground electrodes at the input end,
an edge shape (L) of an edge of the signal electrode side of the ground electrode, in a case of a plane view,
is set to coincide with a first line L 1 obtained by connecting the input end to a location at which the space between the ground electrodes becomes W 2 using a straight line, or
is placed within an area surrounded by first line L 1 and a second line L 2 positioned along a line where a shape of the signal electrode has a rectangular part as a wire-bonding area and a taper part provided from the wire-bonding area to a modulation portion, and a shape of an edge of the signal electrode side of the ground electrode is changed along the shape of the signal electrode wherein an impedance change of the control electrode from the input end to the location at which the space between the ground electrodes becomes W 2 is constant or continuously changes,
the edge shape (L) is not the same as the second line L 2 , and

a space between grounding wires which connect the ground electrodes of the optical waveguide element and the ground lines of the relay substrate is larger than the space W 1 .

2. The optical waveguide element module according to claim 1 ,
wherein the edge shape of the signal electrode side of the ground electrode is set to coincide with the first line L 1 .

3. The optical waveguide element module according to claim 1 , wherein the edge shape of the signal electrode side of the ground electrode is placed within the area surrounded by first line L 1 and second line L 2 , and
is a shape constituted of a plurality of straight lines.

4. The optical waveguide element module according to claim 1 , wherein the edge shape of the signal electrode side of the ground electrode is placed within the area surrounded by first line L 1 and second line L 2 , and
is constituted of a curved line having a single or a plurality of curvature.

5. The optical waveguide element module according to claim 1 , wherein a material of the substrate configuring the optical waveguide element and a material of the relay substrate have different permittivity.

6. An optical waveguide element module comprising:
an optical waveguide element including a substrate having an electro-optic effect, an optical waveguide formed in the substrate, and a control electrode for controlling light waves that propagate through the optical waveguide; and
a terminal substrate which is provided outside the optical waveguide element and has a wire electrically connected to an output end of the control electrode,
the optical waveguide element and the terminal substrate being housed in a case,
wherein the control electrode is formed on the substrate of the optical waveguide element, and is constituted of a signal electrode and ground electrodes which put the signal electrode therebetween,
the wire of the terminal substrate is constituted of a signal line and ground lines which put the signal line therebetween,
a width of the signal electrode at the output end is smaller than a width of the signal line at an input end of the wire,
in the control electrode of the optical waveguide element, a space W 2 between the ground electrodes at a portion away from the output end is narrower than a space W 1 between the ground electrodes at the output end,
an edge shape (L) of an edge of the signal electrode side of the ground electrode, in a case of a plane view,
is set to coincide with a first line L 1 obtained by connecting the output end to a location at which the space between the ground electrodes becomes W 2 using a straight line, or
is placed within an area surrounded by first line L 1 and a second line L 2 positioned along a line where a shape of the signal electrode has a rectangular part as a wire-bonding area and a taper part provided from the wire-bonding area to a modulation portion, and a shape of an edge of the signal electrode side of the ground electrode is changed along the shape of the signal electrode wherein an impedance change of the control electrode from the output end to the location at which the space between the ground electrodes becomes W 2 is constant or continuously changes,
the edge shape (L) is not the same as the second line L 2 , and

a space between grounding wires which connect the ground electrodes of the optical waveguide element and the ground lines of the terminal substrate is larger than the space W 1 .

7. The optical waveguide element module according to claim 6 ,
wherein the edge shape of the signal electrode side of the ground electrode is set to coincide with the first line L 1 .

8. The optical waveguide element module according to claim 6 ,
wherein the edge shape of the signal electrode side of the ground electrode is placed within the area surrounded by first line L 1 and second line L 2 , and
is a shape constituted of a plurality of straight lines.

9. The optical waveguide element module according to claim 6 ,
wherein the edge shape of the signal electrode side of the ground electrode is placed within the area surrounded by first line L 1 and second line L 2 , and
is constituted of a curved line having a single or a plurality of curvature.

10. The optical waveguide element module according to claim 6 , wherein a material of the substrate configuring the optical waveguide element and a material of the terminal substrate have different permittivity.

Assignees

• Sumitomo Osaka Cement Co Ltd
• Sumitomo Osaka Cement Co Ltd

Inventors

• Katou Kei
• Miyazaki Norikazu
• Hosokawa Youichi

Classifications

• G02F1/0356

  controlled by a high-frequency electromagnetic wave component in an electric waveguide structure · CPC title

• G02F1/035 Primary

  in an optical waveguide structure · CPC title

• G02F1/0316

  Electrodes · CPC title

• G02F1/2255

  controlled by a high-frequency electromagnetic component in an electric waveguide structure · CPC title