Integrated optical add/drop device having switching function

• US 20060233486A1
• Filed: 12/31/2002
• Published: 10/19/2006
• Est. Priority Date: 12/31/2002
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: PGT Photonics SPA (Broadcom, Inc.)
• Inventors: Romagnoli, Marco, Gorni, Giacomo, Faccio, Daniele
• Granted Patent: US 7,356,219 B2
• Time in Patent Office: Days
• US Class Current: 385/14
• CPC Class Codes: G02B 2006/12109 Filter
• CPC Class Codes: G02B 2006/12147 Coupler
• CPC Class Codes: G02B 2006/12159 Interferometer
• CPC Class Codes: G02B 6/12007 forming wavelength selective elements, e.g. multiplexer, demultiplexer
• CPC Class Codes: G02B 6/29353 with a wavelength selective element in at least one light guide interferometer arm, e.g. grating, interference filter, resonator
• CPC Class Codes: G02B 6/29355 Cascade arrangement of interferometers
• CPC Class Codes: G02B 6/29383 Adding and dropping
• CPC Class Codes: G02B 6/29395 configurable, e.g. tunable or reconfigurable switching G02B6/35
• CPC Class Codes: G02F 1/3136 of interferometric switch type
• CPC Class Codes: G02F 2203/055 wavelength filtering
• CPC Class Codes: G02F 2203/15 involving resonance effects, e.g. resonantly enhanced interaction
• CPC Class Codes: G02F 2203/50 Phase-only modulation
• CPC Class Codes: G02F 2203/585 Add/drop devices
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0009 using wavelength filters
• CPC Class Codes: H04Q 2011/0015 using splitting combining

Abstract

An integrated optical add/drop device having switching function for use in wavelength division multiplexing optical communication systems, has first and second optical couplers between which first and second interferometric arms of an interferometer are extended. The integrated optical add/drop device has an optical filter having first and second input ports connected to first portions of the first and second interferometric arms and first and second output ports connected to second portions of the first and second interferometric arms. The optical filter acts as a selective switch exchanger for exchanging between one interferometric arm and the other at least one of a plurality of optical signals S (λ1) , S (λ2), . . . , S (λn), received at its input ports and for transmitting the remaining optical signals through its output ports in the first and second interferometric arms. The integrated optical add/drop device also has at least first and second optical shifters located on opposite sides of the optical filter.

Claims

1-10. -10. (canceled)

11. An integrated optical add/drop device having switching function for use in wavelength division multiplexing optical communication systems, comprising first and second interferometric arms of an interferometer comprising:

an optical filter having first and second input ports and first and second output ports, said first input port being connected to a first portion of said first interferometric arm, said second input port being connected to a first portion of said second interferometric arm, said first output port being connected to a second portion of said first interferometric arm, said second output port being connected to a second portion of said second interferometric arm, said optical filter acting as a selective switch exchanger for exchanging between one interferometric arm and the other at least one of a plurality of optical signals S(λ

1), S(λ

2), . . . , S(λ

n), received at its input ports and for transmitting the remaining optical signals through its output ports in said first and second interferometric arms; and

at least first and second optical shifters located on opposite sides of said optical filter.

12. The device according to claim 11, wherein said optical filter is a tunable optical filter.

13. The device according to claim 11, wherein each of said first and second phase shifter introduces a phase shift of 0±

2π

N into each optical signal S1(λ

1), S2(λ

2), . . . , Sn(λ

n), propagating in said first and second interferometric arms when it is in a first state.

14. The device according to any one of claims 11-13, wherein each of said first and second phase shifter introduces a phase shift of π

/2±

2π

N into each optical signal S1(λ

1), S2(λ

2), . . . , Sn(λ

n), propagating in said first and second interferometric arms when it is in a second state.

15. The device according to claim 14, wherein each phase shifter is located in a different interferometric arm.

16. The device according to claim 15, wherein said first phase shifter is located in said first portion of said first interferometric arm and said second phase shifter is located in said second portion of said second interferometric arm.

17. The device according to any one of claims 11-13, wherein said first and second phase shifters are both located on a same one of said first and second interferometric arms.

18. The device according to claim 17, wherein said first phase shifter is located in said first portion of said first interferometric arm and said second phase shifter is located in said second portion of said first interferometric arm.

19. The device according to claim 11, wherein said interferometer is a Mach Zehnder interferometer.

20. A method for adding or dropping optical signals in an integrated optical add/drop device in wavelength division multiplexing optical communications, comprising the steps of:

sending a plurality of optical signals S(λ

1), S(λ

2), . . . , S(λ

n), to respective first portions of first and second interferometric arms;

exchanging between one interferometric arm to the other at least one of said plurality of optical signals S(λ

1), S(λ

2), . . . , S(λ

n);

transmitting the remaining optical signals in respective second portions of said first and second interferometric arms; and

introducing a phase shift on at least one of said first portions and at least one of said second portions of said first and second interferometric arms for switching said integrated optical add/drop device from a first state to a second state.