Electro-optic modulator termination

Patent metadata

Field	Value
Publication number	US-2016170241-A1
Application number	US-201414569016-A
Country	US
Kind code	A1
Filing date	Dec 12, 2014
Priority date	Dec 12, 2014
Publication date	Jun 16, 2016
Grant date	—

Abstract

Embodiments presented in this disclosure generally relate to an electro-optic device that includes one or more modulator portions and a terminator portion. Each modulator portion is disposed along a propagation path of an optical signal and includes a respective first doped region and one or more coupled first electrical contacts. Each modulator portion operates to modulate an optical signal propagating through the first doped region using first electrical signals applied to the electrical contacts. The terminator portion is disposed along the propagation path and proximate to at least one modulator portions, and operates to mitigate effects of droop on the propagating optical signal.

First claim

We claim:

1 . An electro-optic device to provide modulation of an optical signal propagating along a propagation path, the electro-optic device comprising:
one or more modulator portions disposed along the propagation path, each modulator portion including:
a respective first doped region that is at least partially included within the propagation path, and
a respective one or more first electrical contacts coupled with the first doped region,
wherein each modulator portion operates to modulate the optical signal propagating through the first doped region using first electrical signals applied to the one or more first electrical contacts; and
a terminator portion disposed along the propagation path and proximate to at least one modulator portion and which operates to mitigate effects of droop on the propagating optical signal.

2 . The electro-optic device of claim 1 , wherein the terminator portion includes a second doped region that is substantially aligned along the propagation path with a corresponding first doped region.

3 . The electro-optic device of claim 2 , further comprising an undoped buffer region disposed between the second doped region and the corresponding first doped region.

4 . The electro-optic device of claim 3 , wherein the width of the buffer region is between about 0.1 microns and 5 microns.

5 . The electro-optic device of claim 2 , wherein the second doped region is coupled with a respective second electrical contact, and wherein the second electrical contact is driven with second electrical signals to mitigate the effects of droop.

6 . The electro-optic device of claim 1 , wherein the first doped region of the one or more modulator portions includes a respective first pair of doped regions, wherein each doped region is coupled with a respective electrical contact and has a different doping, wherein the first pair of doped regions partially overlaps to define an overlap region, and the overlap region is at least partially included in the propagation path.

7 . The electro-optic device of claim 6 , wherein the second doped region of the one or more terminator portions includes a respective second pair of doped regions, wherein each doped region has a different doping, wherein the second pair of doped regions partially overlaps to define a second overlap region, and the propagation path at least partially includes the second overlap region.

8 . The electro-optic device of claim 7 , wherein each pair of the first and second pairs of doped regions includes one doped region of a first material type, and another doped region of a second material type different from the first material type, and wherein for at least one of the first and second material types, the doped regions of the first and second pairs that have a same material type are separated by an undoped buffer region.

9 . The electro-optic device of claim 1 , further comprising at least a second terminator portion, wherein the one or more modulator portions includes a plurality of modulator portions in series along the propagation path, and wherein a respective terminator portion is disposed proximate to each of a first and a last modulator portion of the plurality of modulator portions.

10 . The electro-optic device of claim 1 , comprising a plurality of modulator portions and a plurality of terminator portions disposed in an alternating arrangement along the propagation path.

11 . The electro-optic device of claim 1 , wherein the one or more modulator portions includes a plurality of modulator portions, wherein the electro-optic device provides multi-level modulation for the optical signal, and each of the plurality of modulator portions provides a respective level of the multi-level modulation.

12 . The electro-optic device of claim 1 , wherein the electro-optic device includes a silicon-insulator-silicon capacitive (SISCAP) structure.

13 . The electro-optic device of claim 1 , wherein at least one first doped region and a portion of at least one of the one or more terminator portions are integrally formed.

14 . A method, comprising:
receiving an optical signal propagating along a length of a waveguide; applying a first electrical signal to a modulator portion of the waveguide to modulate the propagating optical signal; and applying a second electrical signal to a terminator portion of the waveguide to mitigate droop from the modulator portion during application of the first electrical signal.

15 . The method of claim 14 , wherein applying the first electrical signal and applying the second electrical signal at least partially overlap in time.

16 . The method of claim 15 , wherein the second electrical signal includes a direct current (DC) signal.

17 . The method of claim 15 , wherein the modulator portion and the terminator portion are each doped, and are separated by an undoped portion of the waveguide.

18 . An electro-optic device, comprising:
a modulator portion that extends along a length of the electro-optic device, the modulator portion comprising:
a first pair of waveguides, each of the first pair of waveguides coupled to one or more respective electrical contacts and having a different doping, wherein the first pair of waveguides at least partially overlap,
wherein the modulator portion operates to modulate an optical signal propagating substantially along the length of the electro-optic device and at least partially through the overlap of the first pair of waveguides using a first electrical signal applied to the respective one or more electrical contacts; and
a second pair of waveguides, each waveguide of the second pair of waveguides aligned with a respective waveguide of the first pair of waveguides along the length of the electro-optic device, at least one waveguide of the second pair of waveguides being separated from at least one waveguide of the first pair by an undoped buffer region, the second pair of waveguides arranged to receive the modulated optical signal from the modulator portion, wherein the second pair of waveguides operates to mitigate effects of droop on the optical signal.

19 . The electro-optic device of claim 18 , wherein the second pair of waveguides is part of a second modulator portion.

20 . The electro-optic device of claim 18 , wherein the second pair of waveguides is part of a terminator device.

Assignees

• Cisco Tech Inc

Inventors

• Adams Donald Benjamin
• Anderson Sean P
• Webster Mark Andrew
• Traverso Matthew

Classifications

• G02F1/025 Primary

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