High-Speed Underwater Data Transmission System and Method

• US 20090274465A1
• Filed: 05/02/2008
• Published: 11/05/2009
• Est. Priority Date: 05/02/2008
• Status: Active Grant

• Current Assignee: Government of the United States of America
• Original Assignee: Government of the United States of America
• Inventors: Bandyopadhyay, Promode R.
• Granted Patent: US 8,045,859 B2
• Time in Patent Office: Days
• US Class Current: 398/104
• CPC Class Codes: H04B 10/70 Photonic quantum communication
• CPC Class Codes: H04B 13/02 Transmission systems in which the medium consists of the earth or a large mass of water thereon, e.g. earth telegraphy

Abstract

An underwater data transmission system including arrays of nano-meter scaled photon emitters and sensors on an outer surface of an underwater platform. For the emitters, a laser is pulsed to correlate with data packets, providing a beam of photons at a prescribed frequency. Nano-scaled collecting lenses channel the incoming photons to photo-receptors located at a focal plane for the frequency at the base of each lens. A coating on the lenses absorbs photons at the frequency that are not aligned with the longitudinal axes of the lenses or tubes. Nano-wires connect the photo-receptors to a light intensity integrator. The integrator integrates the intensity over a surface area. The output of the integrator is fed to a signal processor to track and process the arriving digital packets.

Claims

1. A system for underwater data transmission, said system comprising:

a photon source capable of providing a beam of electromagnetic radiation at a predetermined frequency with the beam capable of being pulsed to encode data of the underwater data transmission;

an array of photo-receptors configured to collect the electromagnetic radiation;

at least one integrator in communication with a plurality of photo-receptors of said array of photo-receptors, said at least one integrator capable of receiving signals from said plurality of photo-receptors corresponding to an intensity of said electromagnetic radiation collected by said plurality of photo-receptors with said at least one integrator integrating the intensity over said plurality of photo-receptors; and

a signal processor in communication with said at least one integrator, said signal processor capable of receiving signals from said at least one integrator corresponding to the integrated intensity, said signal processor capable of determining the transmitted data based on an intensity-time track of the integrated intensity for the pulsed beam of electromagnetic radiation at the predetermined frequency.

2. The system of claim 1, wherein each photo-receptor of said array of photo-receptors comprises:

an elongated lens having an optical opening therein to collect electromagnetic radiation in a direction aligned with a longitudinal axis of said opening; and

a coating on an interior surface of said opening to absorb the electromagnetic radiation of the predetermined frequency.

3. The system of claim 2, wherein said elongated lens is a carbon nano-tube.

4. The system of claim 2, wherein each said photo-receptor further comprises a nano-scale photo-receptor spaced apart from said elongated lens at a distance corresponding to a focal plane for the electromagnetic radiation.

5. The system of claim 4, wherein said nano-scale photo-receptor comprises at least one sensing molecule selected to emit at least one electron upon absorbing the electromagnetic radiation.

6. The system of claim 5, comprising a plurality of nano-wires connected to said nano-scale photo-receptor and said integrator, said plurality of nano-wires capable of transmitting said at least one electron to said integrator.

7. The system of claim 6, further comprising a first protective coating for covering a front surface of each of said photo-receptors at which the electromagnetic radiation enters said photo-receptors such that the electromagnetic radiation passes through said first protective coating prior to entering said photo-receptors.

8. The system of claim 7, further comprising a second protective coating for covering a rear surface of each of said photo-receptors remote from said front surface.

9. The system of claim 1, wherein portions of said array of photo-receptors are capable of activation in a sequence and wherein said signal processor determines a direction of said pulsed beam based on one of said portions having a maximum intensity for the pulsed beam.

10. The system of claim 1, comprising:

attitude sensors at said photon source and said photo-receptors; and

alignment mirrors at said photon source and said photo-receptors, wherein positions of said alignment mirrors are controllable by said attitude sensors to maintain alignment of said beam between said photon source and said photo-receptors.

11. A photo-receptor to collect electromagnetic radiation of a predetermined frequency, said photo-receptor comprising:

a carbon nano-tube collecting lens capable of collecting the electromagnetic radiation in a direction aligned with a longitudinal axis of said collecting lens;

a coating on an interior surface of said carbon nano-tube to absorb the electromagnetic radiation; and

a nano-scale photo-receptor spaced apart from said collecting lens at a distance corresponding to a focal plane for the electromagnetic radiation, said photo-receptor including at least one sensing molecule wherein said sensing molecule is selectable to emit at least one electron upon absorbing the electromagnetic radiation.

12. The photo-receptor of claim 11, further comprising a plurality of nano-wires capable of transmitting the at least one electron to an integrator for integrating intensities of the electromagnetic radiation collected by said photo-receptor.

13. The photo-receptor of claim 11, further comprising a first protective coating covering said collecting lens in a plane perpendicular to said longitudinal axis such that the electromagnetic radiation passes through said first protective coating prior to entering said collecting lens.

14. The photo-receptor of claim 13, wherein said protective coating is transparent to the electromagnetic radiation.

15. The photo-receptor of claim 14, further comprising a second protective coating for covering a rear surface of each of said photo-receptors remote from said first protective coating.

16. A method for determining a direction of a signal source arriving at an array of photo-receptors, comprising the steps of:

activating a portion of the array of photo-receptors wherein the portion is a plurality of contiguous photo-receptors;

determining, in relation to a time period, an intensity of photons collected by the portion in a direction aligned with the photo-receptors and corresponding to pulses of photons from the signal source at a predetermined frequency;

sequentially activating overlapping portions of the array of photo-receptors and determining intensities;

integrating the intensities over the array to determine the overlapping portions of peaking intensities; and

performing a limited activation sequence about the overlapping portions to refine the direction of the signal source.

17. The method of claim 16, said method further comprising the steps of:

coordinating results for peak intensities from a plurality of arrays; and

reorienting the plurality of arrays to enhance the peak intensities based on the coordinated results.