Polarization division multiplexed (PDM) communication systems and devices and methods of use thereof

Patent metadata

Field	Value
Publication number	US-11742977-B2
Application number	US-202016773951-A
Country	US
Kind code	B2
Filing date	Jan 27, 2020
Priority date	Jan 25, 2019
Publication date	Aug 29, 2023
Grant date	Aug 29, 2023

Abstract

Among the various aspects of the present disclosure is the provision of systems or methods for polarization division multiplexed (PDM) optical transmission. For example, the PDM optical transmission system can comprise a chip with one or more aluminum nanowire filters attached to the surface of the chip, such as division of focal Plane (DoFP) polarimeter filter array bonded on the receiver IC.

First claim

What is claimed is:

1. A polarization division multiplexed (PDM) optical transmission system comprising:
a. two or more optical signal transmitters configured to produce two or more linearly polarized optical signals, wherein each of the two or more linearly polarized optical signals comprises a different and constant signal polarization angle;
b. a transmission medium configured to transmit a polarization division multiplexed signal comprising the two or more linearly polarized optical signals received from the two or more optical signal transmitters; and
c. a signal receiver configured to receive and decode the polarization division multiplexed signal from the transmission medium, the signal receiver comprising a division of focal plane (DoFP) array comprising two or more receiver channels comprising a first and second receiver channel, each receiver channel corresponding to one linearly polarized optical signal, each receiver channel comprising a polarization filter configured to transmit a portion of the PDM signal with the signal polarization angle of the one linearly polarized optical signal, a photodetector configured to convert a light intensity of the portion of the PDM signal transmitted through the polarization filter into an electrical signal, and two or more decoders operatively coupled to the two or more channels comprising a first and second decoder, wherein:
the first decoder comprises a comparator operatively coupled to the first receiver channel and configured to produce a first digital signal comprising 0 or LOW if the electrical signal of the first receiver channel is below a first signal threshold and a first digital signal of 1 or HIGH if the electrical signal is above the first signal threshold; and
the second decoder comprises at least two additional comparators comprising first and second additional comparators operatively coupled to the second receiver channel, and further comprises a multiplexer operatively coupled to the comparator of the first receiver channel and the first and second additional comparators, wherein:
the first and second additional comparators are configured to produce first and second additional digital signals comprising 0 or LOW if the electrical signal of the second receiver channel is below first and second additional signal thresholds, respectively, and first and second additional digital signals of 1 or HIGH if the electrical signal of the second receiver channel is above first and second additional signal thresholds, respectively; and
the multiplexer is configured to select and transmit the first or second additional digital signal based on the first digital signal received from the first receiver channel decoder.

2. The system of claim 1 , wherein the transmission medium is selected from a group consisting of free space, free space with a pair of mirrors, and an optical fiber.

3. The system of claim 1 , wherein the digital signals produced by the two or more decoders are combined into a digital data stream.

4. The system of claim 1 , wherein the two or more linearly polarized optical signals comprise:
a. three linearly polarized optical signals comprising signal polarization angles of 0°, 60° and 120°, respectively; or
b. four linearly polarized optical signals comprising signal polarization angles of 0°, 45°, 90°, and 135°, respectively.

5. The system of claim 1 , wherein the signal receiver is a CMOS integrated chip (IC) and each photodetector of the DoFP array is a high-speed silicon photodiode.

6. The system of claim 1 , wherein:
the signal threshold of each comparator is constant and the first additional signal threshold is not equal to the second additional signal threshold.

7. The system of claim 5 , wherein each polarization filter of the DoFP array comprises an aluminum nanowire filter attached to a surface of the CMOS integrated chip (IC).

8. The system of claim 7 , wherein each polarization filter from the DoFP array has an independent polarization angle matching a signal polarization angle of a corresponding channel of the DofP array.

9. A method of polarization division multiplexing comprising:
a. producing two or more linearly polarized optical signals using two or more optical signal transmitters, wherein each of the two or more linearly polarized optical signals comprises a constant and different signal polarization angle;
b. transmitting a polarization division multiplexed (PDM) signal comprising the two or more linearly polarized optical signals received from the two or more optical signal transmitters through a transmission medium;
c. receiving the PDM signal from the transmission medium using a signal receiver, the signal receiver comprising a division of focal plane (DoFP) array comprising two or more receiver channels, each channel corresponding to one linearly polarized optical signal, each receiver channel comprising: a polarization filter a photodetector, and a decoder;
d. filtering the PDM signals through the polarization filters of the Division of Focal Plane (DoFP) array, each polarization filter configured to transmit a portion of the PDM signal with the signal polarization angle of the one linearly polarized optical signal;
e. converting a light intensity of each portion of the PDM signal transmitted through the polarization filters into an electrical signal using the photodetector for each channel of the DoFP array; and
f. decoding the electrical signals of the at least two receiver channels into at least two digital signals using at least two decoders comprising first and second decoders, wherein:
the first decoder comprises a comparator operatively coupled to the first receiver channel to produce a first digital signal comprising 0 or LOW if the electrical signal of the first receiver channel is below a first signal threshold and a first digital signal of 1 or HIGH if the electrical signal is above the first signal threshold;
the second decoder comprises at least two additional comparators comprising first and second additional comparators operatively coupled to the second receiver channel, and a multiplexer operatively coupled to the comparator of the first receiver channel and the first and second additional comparators, wherein:
the first and second additional comparators produce first and second additional digital signals comprising 0 or LOW if the electrical signal of the second receiver channel is below first and second additional signal thresholds, respectively, and first and second additional digital signals of 1 or HIGH if the electrical signal of the second receiver channel is above first and second additional signal thresholds, respectively; and
the multiplexer selects and transmits the first or second additional digital signal based on the first digital signal received from the first receiver channel decoder.

10. The method of claim 9 , wherein the transmission medium is selected from a group consisting of free space, free space with a pair of mirrors, and an optical fiber.

11. The method of claim 9 , further comprising
combining the digital signals from all channels of the DoFP array into a digital data-stream.

12. The method of claim 9 , wherein the two or more linearly polarized optical signals comprise:
a. three linearly polarized optical signals comprising signal polarization angles of 0°, 60° and 120°, respectively; or
b. four linearly polarized optical signals comprising signal polarization angles of 0°, 45°, 90°, and 135°, respectively.

13. The method of claim 9 , wherein:
the signal threshold of each comparator is constant and the first additional signal threshold is not equal to the second additional signal threshold.

Assignees

• Chamberlain Roger
• Ivanovich Darko
• Gruev Viktor
• Washington University St Louis

Inventors

• Chamberlain Roger
• Ivanovich Darko
• Gruev Viktor

Classifications

• H04J14/06 Primary

  Polarisation multiplex systems · CPC title

• H04B10/116

  Visible light communication · CPC title