Electro-optic (E/O) device with an E/O amplitude modulator and associated methods

Patent metadata

Field	Value
Publication number	US-9645469-B2
Application number	US-201514836011-A
Country	US
Kind code	B2
Filing date	Aug 26, 2015
Priority date	Aug 26, 2015
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

An electro-optic (E/O) device includes an asymmetric optical coupler having an input and first and second outputs, a first optical waveguide arm coupled to the first output of the first asymmetric optical coupler, and a second optical waveguide arm coupled to the second output of the first asymmetric optical coupler. At least one E/O amplitude modulator is coupled to at least one of the first and second optical waveguide arms. An optical combiner is coupled to the first and second optical waveguide arms downstream from the at least one E/O amplitude modulator.

First claim

That which is claimed is:

1. An electro-optic (E/O) device comprising:
a first asymmetric optical coupler having an input and first and second outputs;
a first optical waveguide arm coupled to the first output of said first asymmetric optical coupler;
a second optical waveguide arm coupled to the second output of said first asymmetric optical coupler;
said first and second optical waveguide arms having a same length with first and second optical signals received by said first and second optical waveguide arms having equal phases but at different power levels;
at least one first E/O amplitude modulator coupled to at least one of said first and second optical waveguide arms; and
a first optical combiner coupled to said first and second optical waveguide arms downstream from said at least one first E/O amplitude modulator.

2. The E/O device according to claim 1 further comprising an optical source coupled to the input of said first asymmetric optical coupler and configured to generate a continuous optical input signal.

3. The E/O device according to claim 1 wherein said at least one first E/O amplitude modulator comprises an optical ring modulator.

4. The E/O device according to claim 3 wherein said optical ring modulator comprises a ring having a radius within a range of 5-10 μm.

5. The E/O device according to claim 1 wherein said at least one E/O amplitude modulator comprises:
a first optical ring modulator coupled to said first optical waveguide arm; and
a second optical ring modulator coupled to said second optical waveguide arm.

6. The E/O device according to claim 1 wherein said first asymmetric coupler comprises at least one of an asymmetric multimode interference (MMI) coupler and an asymmetric dc coupler.

7. The E/O device according to claim 1 wherein said first optical combiner comprises a symmetric combiner.

8. The E/O device according to claim 1 wherein said first optical combiner comprises a multimode interference (MMI) Y-junction coupler.

9. The E/O device according to claim 1 further comprising at least one optical phase adjuster coupled to at least one of said first and second optical waveguide arms.

10. The E/O device according to claim 1 further comprising:
a second asymmetric coupler having an input coupled to the second output of said first asymmetrical coupler and having first and second outputs, the first output of said second asymmetric coupler coupled to said second optical waveguide arm;
a third optical waveguide arm coupled to the second output of said second asymmetric coupler;
at least one second E/O amplitude modulator coupled to said third optical waveguide arm; and
a second optical combiner coupled to an output of said first optical combiner and said third optical waveguide arm downstream from said at least one second E/O amplitude modulator.

11. The E/O device according to claim 1 further comprising:
a second asymmetric optical coupler having an input and first and second outputs;
a third optical waveguide arm coupled to the first output of said second asymmetric optical coupler;
a fourth optical waveguide arm coupled to the second output of said second asymmetric optical coupler;
at least one second E/O amplitude modulator coupled to at least one of said third and fourth optical waveguide arms;
a second optical combiner coupled to said third and fourth optical waveguide arms downstream from said at least one second E/O amplitude modulator;
a third asymmetric optical coupler having first and second outputs coupled to respective inputs said first and second asymmetric couplers; and
a third optical combiner having first and second inputs coupled to respective outputs of said first and second combiners.

12. An electro-optic (E/O) device comprising:
an optical source configured to generate a continuous optical input signal;
a first asymmetric optical coupler having an input coupled to said optical source and having first and second outputs;
a first optical waveguide arm coupled to the first output of said first asymmetric optical coupler;
a second optical waveguide arm coupled to the second output of said first asymmetric optical coupler;
said first and second optical waveguide arms having a same length with first and second optical signals received by said first and second optical waveguide arms having equal phases but at different power levels;
a first E/O amplitude modulator coupled to said first optical waveguide arm;
a second E/O amplitude modulator coupled to said second optical waveguide arm; and
a first symmetric optical combiner coupled to said first and second optical waveguide arms downstream from said first and second E/O amplitude modulators.

13. The E/O device according to claim 12 wherein said first E/O amplitude modulator comprises a first optical ring modulator, and said second E/O amplitude modulator comprises a second optical ring modulator.

14. The E/O device according to claim 13 wherein said first and second optical ring modulators each comprises a ring having a radius within a range of 5-10 μm.

15. The E/O device according to claim 12 wherein said first asymmetric coupler comprises at least one of an asymmetric multimode interference (MMI) coupler and an asymmetric dc coupler.

16. The E/O device according to claim 12 wherein said first optical combiner comprises a multimode interference (MMI) Y-junction coupler.

17. The E/O device according to claim 12 further comprising at least one optical phase adjuster coupled to at least one of said first and second optical waveguide arms.

18. The E/O device according to claim 12 further comprising:
a second asymmetric coupler having an input coupled to the second output of said first asymmetrical coupler and having first and second outputs, the first output of said second asymmetric coupler coupled to said second optical waveguide arm;
a third optical waveguide arm coupled to the second output of said second asymmetric coupler; and
a second optical combiner coupled to an output of said first optical combiner and said third optical waveguide arm.

19. The E/O device according to claim 12 further comprising:
a second asymmetric optical coupler having an input and first and second outputs;
a third optical waveguide arm coupled to the first output of said second asymmetric optical coupler;
a fourth optical waveguide arm coupled to the second output of said second asymmetric optical coupler;
at least one third optical E/O amplitude modulator coupled to at least one of said third and fourth optical waveguide arms;
a second optical combiner coupled to said third and fourth optical waveguide arms downstream from said at least one third E/O amplitude modulator;
a third asymmetric optical coupler having first and second outputs coupled to respective inputs said first and second asymmetric couplers; and
a third optical combiner having first and second inputs coupled to respective outputs of said first and second combiners.

20. A method for modulating an optical input signal using an electro-optic (E/O) device comprising a first asymmetric optical coupler having an input and first and second outputs; a first optical waveguide arm coupled to the first output of the first asymmetric optical coupler; a second optical waveguide arm coupled to the second output of the first asymmetric optical coupler; at least one first E/O amplitude modulator coupled to at least one of the first and second optical waveguide arms; and a first optical combiner coupled to the first and second optica

Assignees

• St Microelectronics Crolles 2 Sas
• St Microelectronics Sa

Inventors

• Lemaitre Patrick
• Carpentier Jean-Francois
• Baudot Charles
• Manouvrier Jean-Robert

Classifications

• G02F2203/15

  involving resonance effects, e.g. resonantly enhanced interaction · CPC title

• G02F2001/212

  Physics · mapped topic

• G02F1/225 Primary

  in an optical waveguide structure · CPC title

• G02F1/2257

  the optical waveguides being made of semiconducting material · CPC title

• G02F1/025

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