Method for muxing orthogonal modes using modal correlation matrices

• US 10,326,526 B2
• Filed: 09/08/2017
• Issued: 06/18/2019
• Est. Priority Date: 09/08/2016
• Status: Active Grant

• Current Assignee: Nxgen Partners Ip, LLC (NxGen Partners LLC)
• Original Assignee: Nxgen Partners Ip, LLC (NxGen Partners LLC)
• Inventors: Ashrafi, Solyman
• Primary Examiner(s): Liu, Li
• Application Number:
  US15/699,334
• Publication Number:
  US 20180069631A1
• Time in Patent Office: 648 Days
• Field of Search: None
• CPC Class Codes: G02B 6/02042 Multicore optical fibres
• CPC Class Codes: G02B 6/024 with polarisation maintaining properties
• CPC Class Codes: G02B 6/14 Mode converters
• CPC Class Codes: G02B 6/262 Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements
• CPC Class Codes: G02B 6/2726 in or on light guides, e.g. polarisation means assembled in a light guide
• CPC Class Codes: G02B 6/4246 Bidirectionally operating package structures
• CPC Class Codes: G02B 6/43 Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections
• CPC Class Codes: H04B 10/2507 for the reduction or elimination of distortion or dispersion
• CPC Class Codes: H04B 10/2581 Multimode transmission
• CPC Class Codes: H04B 10/516 Details of coding or modulation
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems
• CPC Class Codes: H04J 14/0307 Multiplexers; Demultiplexers
• CPC Class Codes: H04J 14/04 Mode multiplex systems
• CPC Class Codes: H04J 14/052 using multicore fibre mode multiplex systems H04J14/04
• CPC Class Codes: H04J 14/06 Polarisation multiplex systems
• CPC Class Codes: H04J 14/07 Orbital angular momentum [OAM] multiplex systems
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 9/0852 Quantum cryptography transmission systems employing electromagnetic waves other than radio waves, e.g. light, infrared H04B10/00; wavelength-division multiplex systems H04J14/02; WDM arrangements H04J14/03

Abstract

A method for transmitting an orthogonal function processed signal over a communications link on a fiber involves generating at least one mode crosstalk matrix illustrating mode crosstalk between transmitted modes and adjacent modes within the fiber. Adjacent modes to be multiplexed together are selected based on entries within the generated mode crosstalk matrix being less than or equal to a predetermined value. The transmitted modes and the selected adjacent modes are multiplexed together into the orthogonal function processed signal for transmission on the communications link on the fiber.

Claims

1. A method for transmitting an orthogonal function processed signal over a communications link on a fiber, comprising:

generating at least one mode crosstalk matrix illustrating mode crosstalk between transmitted modes and adjacent modes within the fiber, wherein the step of generating further comprises;

applying an inverse of an orthogonal function to each of a plurality of adjacent modes for each of a plurality of transmitted modes of an orthogonal function processed signal to generate a second signal having planar face front components associated with each of the plurality of adjacent modes;

filtering each of the second signals with a filter to pass through the planar face front components of each of the second signals applied to each of the plurality of adjacent modes and block other adjacent mode non-planar face front components from each of the second signals;

measuring a power level for each of the plurality of adjacent modes of each of the second signals having filtered planar face front components;

populating each row associated with each of the transmitted modes in the mode crosstalk matrix with the measured power level for each of the plurality of adjacent modes;

selecting adjacent modes to multiplex together based on entries within the generated at least one mode crosstalk matrix being less than or equal to a predetermined value; and

multiplexing the transmitted modes and the selected adjacent modes together into the orthogonal function processed signal for transmission on the communications link on the fiber.

2. The method of claim 1, wherein the transmitted modes and adjacent modes comprise orthogonal function modes.

3. The method of claim 2, wherein the orthogonal function modes comprise at least one of Hermite-Gaussian modes, Laguerre-Gaussian modes and Ince-Gaussian modes.

4. The method of claim 1, wherein the step of multiplexing further comprises multiplexing the transmitted modes and the selected adjacent modes together onto the communications link on the fiber using at least one of wavelength division multiplexing (WDM) and dense wavelength division multiplexing (DWDM).

5. The method of claim 1, wherein the step of multiplexing further comprises multiplexing the transmitted modes and the selected adjacent modes together onto the communications link on the fiber using a combination of mode division multiplexing, wavelength division multiplexing and polarization multiplexing.

6. The method of claim 1, wherein the step of applying further comprises applying the inverse of the orthogonal function for each of the plurality of adjacent modes within the orthogonal function processed signal to the orthogonal function processed signal using an inverse hologram implemented within a second spatial light modulator to generate the second signal having the planar face front components associated with the plurality of adjacent modes within the orthogonal function processed signal.

7. The method of claim 1, wherein the step of selecting further comprises selecting the adjacent modes using quantum level overlay to combat channel impairments and interference.

8. A method for transmitting an orthogonal function processed signal over a communications link on a fiber, comprising:

generating at least one mode crosstalk matrix illustrating mode crosstalk between transmitted orthogonal modes and adjacent orthogonal modes within the fiber, wherein the step of generating further comprises;

(a) transmitting a first mode of a plurality of modes of the orthogonal function processed signal over the communications link between a transmitter and a receiver;

(b) receiving the transmitted mode of the orthogonal function processed signal over the communications link at the receiver;

(c) applying an inverse of the orthogonal function to each of a plurality of adjacent modes within the orthogonal function processed signal to generate a second signal having planar face front components associated with the plurality of adjacent modes within the signal;

(d) filtering the second signal with a filter to pass through the planar face front components of the second signal applied to each of the plurality of adjacent modes and block other adjacent mode non-planar face front components from the second signal;

(e) measuring a power level for each of the plurality of adjacent modes of the second signal having filtered planar face front components; and

(f) populating a row associated with the transmitted mode in the mode crosstalk matrix with the measured power level for each of the plurality of adjacent modes;

(g) transmitting a next mode of the plurality of modes of the orthogonal function processed signal over the communications link between the transmitter and the receiver; and

(h) repeating steps (b)-(g) for each of the plurality of modes of the orthogonal function processed signal until each row of the mode crosstalk matrix has been populated;

selecting adjacent orthogonal modes to multiplex together based on entries within the generated at least one mode crosstalk matrix being less than or equal to a predetermined value;

multiplexing the transmitted modes and the selected adjacent orthogonal modes together into the orthogonal function processed signal for transmission on the communications link on the fiber; and

transmitting the orthogonal function processed signal on the communications link on the fiber.

9. The method of claim 8, wherein the orthogonal functions modes comprise at least one of Hermite-Gaussian modes, Laguerre-Gaussian modes and Ince-Gaussian modes.

10. The method of claim 8, wherein the step of multiplexing further comprises multiplexing the transmitted modes and the selected adjacent orthogonal modes together onto the communications link on the fiber using at least one of wavelength division multiplexing (WDM) and dense wavelength division multiplexing (DWDM).

11. The method of claim 8, wherein the step of multiplexing further comprises multiplexing the transmitted modes and the selected adjacent orthogonal modes together onto the communications link on the fiber using a combination of mode division multiplexing, wavelength division multiplexing and polarization multiplexing.

12. The method of claim 8, wherein the step of selecting further comprises selecting the adjacent modes using quantum level overlay to combat channel impairments and interference.

13. The method of claim 8, wherein the step of applying further comprises applying the inverse of the orthogonal function for each of the plurality of adjacent modes within the orthogonal function processed signal to the orthogonal function processed signal using an inverse hologram implemented within a second spatial light modulator to generate the second signal having the planar face front components associated with the plurality of adjacent modes within the orthogonal function processed signal.

14. A transmitter circuitry for transmitting an orthogonal function processed signal over a communications link on a fiber, comprising:

a first input for receiving a generated at least one mode crosstalk matrix illustrating mode crosstalk between transmitted modes and adjacent modes within the fiber, wherein the generated at least one mode crosstalk matrix is generated by;

(a) transmitting a first mode of a plurality of modes of the orthogonal function processed signal over the communications link between a transmitter and a receiver;

(b) receiving the transmitted mode of the orthogonal function processed signal over the communications link at the receiver;

(c) applying an inverse of the orthogonal function to each of a plurality of adjacent modes within the orthogonal function processed signal to generate a second signal having planar face front components associated with the plurality of adjacent modes within the signal;

(d) filtering the second signal with a filter to pass through the planar face front components of the second signal applied to each of the plurality of adjacent modes and block other adjacent mode non-planar face front components from the second signal;

(e) measuring a power level for each of the plurality of adjacent modes of the second signal having filtered planar face front components; and

(f) populating a row associated with the transmitted mode in the mode crosstalk matrix with the measured power level for each of the plurality of adjacent modes;

(g) transmitting a next mode of the plurality of modes of the orthogonal function processed signal over the communications link between the transmitter and the receiver; and

(h) repeating steps (b)-(g) for each of the plurality of modes of the orthogonal function processed signal until each row of the mode crosstalk matrix has been populated;

a processor configured to select adjacent modes to multiplex together based on entries within the mode crosstalk matrix being less than or equal to a predetermined value;

multiplexing circuitry for multiplexing the transmitted modes and the selected adjacent modes together into the orthogonal function processed signal for transmission on the communications link on the fiber; and

a transceiver for transmitting the orthogonal function processed signal on the communications link on the fiber.

15. The transmitter circuitry of claim 14, wherein the transmitted modes and adjacent modes comprise orthogonal function modes.

16. The transmitter circuitry of claim 15, wherein the orthogonal function modes comprise at least one of Hermite-Gaussian modes, Laguerre-Gaussian modes and Ince-Gaussian modes.

17. The transmitter circuitry of claim 14, wherein the multiplexing circuit is further configured to multiplex the transmitted modes and the selected adjacent modes together onto the communications link on the fiber using at least one of wavelength division multiplexing (WDM) and dense wavelength division multiplexing (DWDM).

18. The transmitter circuitry of claim 14, wherein the multiplexer is further configured to multiplex the transmitted modes and the selected adjacent modes together onto the communications link on the fiber using a combination of mode division multiplexing, wavelength division multiplexing and polarization multiplexing.

19. The transmitter circuitry of claim 14, wherein the processor is further configured to select the adjacent modes using quantum level overlay to combat channel impairments and interference.

20. A transmitter circuitry for transmitting an orthogonal function processed signal over a communications link on a fiber, comprising:

a first input for receiving a generated at least one mode crosstalk matrix illustrating mode crosstalk between transmitted modes and adjacent modes within the fiber, wherein the generated at least one mode crosstalk matrix is generated by;

applying an inverse of an orthogonal function to each of a plurality of adjacent modes for each of a plurality of transmitted modes of an orthogonal function processed signal to generate a second signal having planar face front components associated with each of the plurality of adjacent modes;

filtering each of the second signals with a filter to pass through the planar face front components of each of the second signals applied to each of the plurality of adjacent modes and block other adjacent mode non-planar face front components from each of the second signals;

measuring a power level for each of the plurality of adjacent modes of each of the second signals having filtered planar face front components;

populating each row associated with each of the transmitted modes in the mode crosstalk matrix with the measured power level for each of the plurality of adjacent modes;

a processor configured to select adjacent modes to multiplex together based on entries within the mode crosstalk matrix being less than or equal to a predetermined value;

multiplexing circuitry for multiplexing the transmitted modes and the selected adjacent modes together into the orthogonal function processed signal for transmission on the communications link on the fiber; and

a transceiver for transmitting the orthogonal function processed signal on the communications link on the fiber.

21. The transmitter circuitry of claim 20, wherein the transmitted modes and adjacent modes comprise orthogonal function modes.

22. The transmitter circuitry of claim 21, wherein the orthogonal function modes comprise at least one of Hermite-Gaussian modes, Laguerre-Gaussian modes and Ince-Gaussian modes.