OPTICAL MODULE AND OPTICAL TRANSMITTER

• US 20150063809A1
• Filed: 07/07/2014
• Published: 03/05/2015
• Est. Priority Date: 08/29/2013
• Status: Active Grant

• Current Assignee: Fujitsu Optical Components Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Optical Components Limited (Fujitsu Limited)
• Inventors: SUGIYAMA, Masaki, SASAKI, Seimi, TANAKA, Takehito
• Granted Patent: US 9,231,728 B2
• Time in Patent Office: Days
• US Class Current: 398/65
• CPC Class Codes: G02F 1/0121 Operation of devices; Circuit arrangements, not otherwise provided for in this subclass
• CPC Class Codes: G02F 1/212 Mach-Zehnder type
• CPC Class Codes: G02F 1/2255 controlled by a high-frequency electromagnetic component in an electric waveguide structure
• CPC Class Codes: G02F 2201/127 travelling wave
• CPC Class Codes: H04J 14/06 Polarisation multiplex systems

Abstract

An optical module includes a waveguide substrate having an optical waveguide and electrodes that apply electronic signals to the optical waveguide; a relay substrate disposed adjacently to the waveguide substrate; and a termination substrate disposed sandwiching the waveguide substrate with the relay substrate. The electrodes respectively have a first wiring portion connected from the relay substrate through the waveguide substrate to the termination substrate and a second wiring portion extending from the first wiring portion and branching on the termination substrate. In the second wiring portion, one branched wiring portion has a capacitor and a termination resistor, and another branched wiring portion extends through a bias resistor to a DC electrode on the relay substrate. The second wiring portion is divided into a first group extending in a first direction along the optical waveguide and a second group extending in a direction opposite to the first direction.

Claims

1. An optical module comprising:

a waveguide substrate having an optical waveguide and multiple electrodes causing electronic signals to be applied to the optical waveguide;

a relay substrate disposed adjacently to the waveguide substrate; and

a termination substrate disposed adjacently to the waveguide substrate on a side opposite to the relay substrate and thereby, sandwiching the waveguide substrate therebetween, wherein

the electrodes respectively have a first wiring portion connected from the relay substrate through the waveguide substrate to the termination substrate and a second wiring portion extending from the first wiring portion and branching on the termination substrate,

in the second wiring portion, one branched wiring portion has a capacitor and a termination resistor, and another branched wiring portion is extended through a bias resistor to a DC electrode on the relay substrate, and

the second wiring portion is divided into a first group extending in a first direction along the optical waveguide and a second group extending in a direction opposite to the first direction.

3. The optical module according to claim 1, wherein

the other branched wiring portion is led out to a back surface of the termination substrate through a via of the termination substrate, and

the bias resistor is disposed on the back surface of the termination substrate.

4. The optical module according to claim 3, wherein the one branched wiring portion and the other branched wiring portion are disposed at substantially the same positions on a front surface and the back surface of the termination substrate.

5. The optical module according to claim 1, wherein the termination substrate is integrated with a carrier substrate disposed on a temperature control cooler.

6. The optical module according to claim 5, wherein the relay substrate is integrated with the carrier substrate.

7. The optical module according to claim 5, wherein

the carrier substrate is a laminated substrate, and

the other branched wiring portion is connected to inner layer wiring of the carrier substrate through a via of the carrier substrate.

11. The optical module according to claim 5, wherein a groove housing the waveguide substrate is formed in a front surface of the carrier substrate.

12. The optical module according to claim 11, wherein the groove has a depth making the front surface of the carrier substrate flush with a front surface of the waveguide substrate.

2. An optical module comprising:

an optical waveguide having a pair of parallel waveguides;

a pair of electrodes disposed along the pair of parallel waveguides and to which electronic signals are applied;

a waveguide substrate having the pair of optical waveguides and the pair of electrodes in plural;

a relay substrate disposed adjacently to the waveguide substrate; and

a termination substrate disposed adjacently to the waveguide substrate on a side opposite to the relay substrate and thereby, sandwiching the waveguide substrate therebetween, wherein

the electrodes respectively have a first wiring portion extended from the relay substrate through the waveguide substrate to the termination substrate and a second wiring portion extending from the first wiring portion and branching on the termination substrate,

in the second wiring portion, one branched wiring portion has a capacitor and a termination resistor, and another branched wiring portion is extended through a bias resistor to a DC electrode on the relay substrate, and

the second wiring portion is divided into a first group extending in a first direction along the optical waveguide and a second group extending in a direction opposite to the first direction.

15. The optical module according to claim 2, wherein

the other branched wiring portion is led out to a back surface of the termination substrate through a via of the termination substrate, and

the bias resistor is disposed on the back surface of the termination substrate.

16. The optical module according to claim 15, wherein the one branched wiring portion and the other branched wiring portion are disposed at substantially the same positions on a front surface and the back surface of the termination substrate.

17. The optical module according to claim 2, wherein the termination substrate is integrated with a carrier substrate disposed on a temperature control cooler.

18. The optical module according to claim 17, wherein the relay substrate is integrated with the carrier substrate.

19. The optical module according to claim 17, wherein

the carrier substrate is a laminated substrate, and

the other branched wiring portion is connected to inner layer wiring of the carrier substrate through a via of the carrier substrate.

8. An optical module comprising:

a waveguide substrate having an optical waveguide and multiple electrodes that cause electronic signals to be applied to the optical waveguide;

a relay substrate disposed adjacently to the waveguide substrate; and

a termination substrate disposed adjacently to the waveguide substrate on a side opposite to the relay substrate and thereby, sandwiching the waveguide substrate therebetween, wherein

in the second wiring portion, one branched wiring portion has a capacitor and a termination resistor, and another branched wiring portion is extended through a bias resistor and a carrier substrate to a DC electrode on the relay substrate, and

the bias resistor is disposed at an inner layer wiring portion of the carrier substrate.

9. An optical module comprising:

a waveguide substrate having an optical waveguide and multiple electrodes that cause electronic signals to be applied to the optical waveguide;

a relay substrate disposed adjacently to the waveguide substrate; and

a termination substrate disposed adjacently to the waveguide substrate on a side opposite to the relay substrate and thereby, sandwiching the waveguide substrate therebetween, wherein

in the second wiring portion, one branched wiring portion has a capacitor and a termination resistor, and another branched wiring portion is extended through a bias resistor and a carrier substrate to a DC electrode on the relay substrate, and

the one branched wiring portion is led out to a back surface of the termination substrate through a via of the termination substrate, and

the capacitor and the termination resistor are disposed on a back surface of the carrier substrate.

10. The optical module according to claim 9, wherein another one or more vias adjacent to the via of the other branched wiring portion are regarded as grounded ground electrodes.

20. The optical module according to claim 9, wherein a groove housing the waveguide substrate is formed in a front surface of the carrier substrate.

21. The optical module according to claim 20, wherein the groove has a depth making the front surface of the carrier substrate flush with a front surface of the waveguide substrate.

13. An optical transmitter comprising:

an optical module including;

a waveguide substrate having an optical waveguide and multiple electrodes that cause electronic signals to be applied to the optical waveguide;

a relay substrate disposed adjacently to the waveguide substrate; and

a termination substrate disposed adjacently to the waveguide substrate on a side opposite to the relay substrate and thereby, sandwiching the waveguide substrate therebetween, wherein

the electrodes respectively have a first wiring portion connected from the relay substrate through the waveguide substrate to the termination substrate and a second wiring portion extending from the first wiring portion and branching on the termination substrate,

in the second wiring portion, one branched wiring portion has a capacitor and a termination resistor, wherein another branched wiring portion is extended through a bias resistor to a DC electrode on the relay substrate, and

the second wiring portion is divided into a first group extending in a first direction along the optical waveguide and a second group extending in a direction opposite to the first direction;

a data generating unit configured to supply as the electronic signals and to the multiple electrodes individually, data for transmission, and configured to supply a drive signal for modulation by the optical waveguide through the DC electrode; and

a bias control circuit providing control such that polarization states of light of the optical waveguide are orthogonal to each other.

14. The optical transmitter according to claim 13, wherein

the other branched wiring portion is led out to a back surface of the termination substrate through a via of the termination substrate, and

the bias resistor is disposed on the back surface of the termination substrate.