Granted Patent B1

US 7,102,821 · App. 10/661,452 · Granted Sep 5, 2006

Abstract

Claims (66)

1. A re-configurable channel dropping de-multiplexer, comprising:

an input;

a first polarizing port optically coupled to the input;

a first polarization modulator optically coupled to the first polarizing port;

a polarization beam splitter (PBS) having a first side that is optically coupled to the first polarization modulator at a side opposite to the first polarizing port;

a second polarization modulator optically coupled to the PBS at a second side of the PBS that is opposite to the first side;

a second polarizing port optically coupled to the second polarization modulator at a side opposite to the PBS;

a multiple-channel output optically coupled to the second polarizing port; and

an isolator core optically coupled to the PBS at a third side of the PBS that is not parallel to either of the first two sides.

2. A cascaded re-configurable system having two or more re-configurable channel dropping de-multiplexers, comprising:

a first re-configurable channel dropping de-multiplexer, comprising:

an input for receiving a plurality of channels;

a first polarizing port optically coupled to the input;

a first polarization modulator optically coupled to the first polarizing port;

a polarization beam splitter (PBS) having a first side that is optically coupled to the first polarization modulator at a side opposite to the first polarizing port;

a second polarization modulator optically coupled to the PBS at a second side of the PBS that is opposite to the first side;

a second polarizing port optically coupled to the second polarization modulator at a side opposite to the PBS; and

a multiple-channel output optically coupled to the second polarizing port; and

a second re-configurable channel dropping de-multiplexer, optically coupled to the first re-configurable channel dropping de-multiplexer, comprising:

an input, coupled to the multiple-channel output of the first re-configurable channel dropping de-multiplexer;

a first polarizing port optically coupled to the input;

a first polarization modulator optically coupled to the first polarizing port;

a polarization beam splitter (PBS) having a first side that is optically coupled to the first polarization modulator at a side opposite to the first polarizing port;

a second polarization modulator optically coupled to the PBS at a second side of the PBS that is opposite to the first side;

a second polarizing port optically coupled to the second polarization modulator at a side opposite to the PBS; and

a multiple-channel output optically coupled to the second polarizing port, wherein each re-configurable channel dropping de-multiplexer further comprises a first quarter-wave (λ/4) plate optically coupled to the PBS at a side of the PBS that is not parallel to either of the first two sides.

3. A re-configurable channel dropping de-multiplexer, comprising:

an input;

a first polarizing port optically coupled to the input;

a first polarization modulator optically coupled to the first polarizing port;

a polarization beam splitter (PBS) having a first side that is optically coupled to the first polarization modulator at a side opposite to the first polarizing port;

a second polarization modulator optically coupled to the PBS at a second side of the PBS that is opposite to the first side;

a second polarizing port optically coupled to the second polarization modulator at a side opposite to the PBS;

a multiple-channel output optically coupled to the second polarizing port; and

a first quarter-wave (λ/4) plate optically coupled to the PBS at a third side of the PBS that is not parallel to either of the first two sides.

4. The de-multiplexer of claim 3 , further comprising a second λ/4 plate optically coupled to the PBS at a fourth side of the PBS that is opposite to the third side and a mirror optically coupled to the second λ/4 plate at a side opposite to the PBS.

5. The de-multiplexer of claim 4 , further comprising an optical channel band pass filter optically coupled to the first λ/4 plate at a side opposite to the PBS.

6. The de-multiplexer of claim 5 , further comprising a third λ/4 plate optically coupled to the optical channel band pass filter at a side opposite to the first λ/4 plate.

7. The de-multiplexer of claim 6 , further comprising:

a third polarizing port optically coupled to the third λ/4 plate at a side opposite to the optical channel band pass filter; and

a single-channel output optically coupled to the third polarizing port.

8. The de-multiplexer of claim 7 functioning in a first operational state, wherein the first and the second polarization modulators are configured so as to rotate the orientation of plane polarized light by 90 degrees; and wherein the input receives and directs a plurality of optical channels to both the second polarizing port and the third polarizing port such that a single dropped channel is routed to the third polarizing port and such that one or more remaining express channels are routed to the second polarizing port.

9. The de-multiplexer of claim 7 functioning in a second operational state, wherein the first and the second polarization modulators are configured so as to not change the polarization plane orientation of plane polarized light; and wherein the input receives and directs a plurality of optical channels to the second polarizing port and no optical channels are directed to the third polarizing port.

10. The de-multiplexer of claim 3 , further comprising an isolator core optically coupled to the PBS at a side of the PBS that is not parallel to either of the first two sides.

11. The de-multiplexer of claim 5 , wherein the optical channel band pass filter comprises a thin film band pass filter.

12. The de-multiplexer of claim 6 , operating as a channel adding multiplexer, wherein the multiple-channel output serves as a multiple-channel input for receiving a plurality of express channels, the single-channel output serves as a single-channel input, the input serves as an output, and the multiple-channel input is combined with the single-channel input to the output.

13. A re-configurable channel dropping de-multiplexer, comprising:

an input;

a first polarizing port optically coupled to the input;

a first polarization modulator optically coupled to the first polarizing port;

a polarization beam splitter having a first side s 1 that is optically coupled to the first polarization modulator at a side opposite to the first polarizing port;

a second polarization modulator optically coupled to the PBS at a side s 3 of the PBS that is not parallel to the first side s 1 ;

a second polarizing port optically coupled to the second polarization modulator at a side opposite to the PBS;

a multiple-channel output optically coupled to the second polarizing port; and

a first quarter-wave (λ/4) plate optically coupled to the PBS at a side s 2 of the PBS that is opposite to the first side s 1 .

14. The de-multiplexer of claim 13 , further comprising:

a second λ/4 plate optically coupled to the PBS at a side s 4 of the PBS opposite to the side s 3 ; and

a mirror optically coupled to the second λ/4 plate at a side opposite to the PBS.

15. The de-multiplexer of claim 14 , further comprising:

an optical channel band pass filter optically coupled to the first λ/4 plate at a side opposite to the PBS;

a third λ/4 plate optically coupled to the optical channel band pass filter at a side opposite to the first λ/4 plate;

a third polarizing port optically coupled to the third λ/4 plate at a side opposite to the optical channel band pass filter; and

a single-channel output optically coupled to the third polarizing port.

16. The de-multiplexer of claim 15 operating in a first state, further comprising a plurality of optical channels λ 1 –λ n passing through the re-configurable channel dropping de-multiplexer from the first polarizing port to both the second polarizing port and the third polarizing port such that a single dropped channel λ d is routed to the third polarizing port and one or more remaining express channels are routed to the second polarizing port.

17. The de-multiplexer of claim 15 operating in a second state, further comprising a plurality of optical channels λ 1 –λ n passing through the re-configurable channel dropping de-multiplexer wherein all the channels are routed to the second polarizing port.

18. The cascaded re-configurable system of claim 2 , wherein each re-configurable channel dropping de-multiplexer further comprises an isolator core optically coupled to the PBS at a side of the PBS that is not parallel to either of the first two sides.

Assignments (8)