Methods and systems for avoiding transmission-channel disruptions

Abstract

Various embodiments of the present invention are directed to methods and systems for circumventing, and altering transmission-channel users of, transmission-channel disruptions. In one embodiment of the present invention, a source encodes information in a first signal and transmits the first signal in a source channel to a multiplexer. The multiplexer distributes the first signal over N transmission channels. A demultiplexer combines the signals distributed over the N transmission channels into a second signal encoding of the information. The distribution system also includes a detector that receives the second signal output from the demultiplexer, and one or more detectors that receive one or more additional signals output from the demultiplexer. The additional signals are produced by the demultiplexer when a disruption occurs in one or more of the transmission channels and are used to alert transmission-channel users of the disruption.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates various transmission channels employed in a transaction between a customer and a merchant.

FIG. 2 illustrates a cubic cavity.

FIG. 3 illustrates a three-dimensional right-handed coordinate system with two independent polarization vectors and a normalized wavevector as basis vectors.

FIG. 4 illustrates a representation of electric and magnetic field components of an electromagnetic field in the right-handed coordinate system shown in FIG. 3.

FIG. 5 is an energy level diagram of a quantized electromagnetic field.

FIG. 6 illustrates a probability amplitude associated with a pulse output from a source and transmitted in an optical fiber to a detector.

FIG. 7A illustrates a representation of an optical beamsplitter.

FIG. 7B illustrates reflections and transmissions of two electric fields input to the beamsplitter shown in FIG. 7A.

FIG. 8 illustrates a 50:50 beamsplitter that receives a photon in a first input channel and a vacuum state in a second input channel.

FIG. 9 illustrates a 50:50 beamsplitter that simultaneously receives a photon in a first input channel and a photon in a second input channel.

FIG. 10 illustrates an example of a polarizing beamsplitter that receives linear superposition of states comprising both vertically and horizontally polarized photons in both input channels.

FIG. 11A illustrates a Mach-Zehnder interferometer.

FIG. 11B is a plot of probability distributions associated with detecting output states of the Mach-Zehnder interferometer shown in FIG. 11A.

FIG. 12 illustrates a coupler and optical-fiber-based implementation of the Mach-Zehnder interferometer shown in FIG. 11A.

FIGS. 13A-13C illustrate a Bloch sphere representation of a qubit.

FIG. 14 illustrates an example of encoding and decoding qubits in polarization states of photons.

FIG. 15 illustrates an example of encoding and decoding qubits in time-bins.

FIG. 16A illustrates a distribution system that distributes a signal in N transmission channels and represents one of many embodiments of the present invention.

FIG. 16B illustrates an example of a distribution-system response to a transmission-channel disruption that represents one of many embodiments of the present invention.

FIG. 17 illustrates an optical signal distribution system that represents one of many embodiments of the present invention.

FIGS. 18A-18B illustrate determining an arrangement of beamsplitters in a demultiplexer, based on an arrangement of beamsplitters in a multiplexer of the optical signal distribution system shown in FIG. 17 that represents one of many embodiments of the present invention.

FIG. 19A shows reflections and transmissions of signals through beamsplitters in a multiplexer of an optical signal distribution system that represents an embodiment of the present invention.

FIG. 19B shows reflection and transmission coefficients associated with the beamsplitters shown in FIG. 19A that represents one or many embodiments of the present invention.

FIG. 20A shows a general formulation of electric field reflections and transmissions in beamsplitters of a demultiplexer that represents one of many embodiments of the present invention.

FIG. 20B shows electric field reflections and transmissions output from the beamsplitters in the demultiplexer, shown in FIG. 17, that represents one of many embodiments of the present invention.

FIG. 21 illustrates a quantum signal-based application of the optical signal distribution system, shown in FIG. 17, that represents one of many embodiments of the present invention.

FIG. 22 illustrates an optical signal distribution system that includes phase shifts in transmission channels and represents one of many embodiments of the present invention.

FIGS. 23A-23B illustrate an example optical signal distribution system that includes transmission channel phase shifts and represents one of many embodiments of the present invention.

FIG. 24 illustrates an optical signal distribution system comprising couplers and optical fibers that represents one or many embodiments of the present invention.

Claims

1. A signal distribution system for circumventing and altering transmission channel users of transmission-channel disruptions, the signal distribution system comprising: a source that encodes information in a first signal and transmits the first signal in a source channel;a multiplexer that receives the first signal from the source channel and distributes the signal over N transmission channels;a demultiplexer that combines the signal distributed over the N transmission channels into a second signal encoding the information;a detector that detects the second signal output from the demultiplexer; andone or more detectors that detect one or more additional signals output from the demultiplexer, the additional signals produced by the demultiplexer when a disruption occurs in one or more of the transmission channels and alerts transmission-channel users of the disruption.

2. The distribution system of claim 1 wherein the multiplexer further comprises N−1 beamsplitters, each beamsplitter mathematically represented by:

3. The distribution system of claim 1 wherein the demultiplexer further comprises N−1 beamsplitters, each beamsplitter mathematically represented by:

4. The distribution system of claim 1 wherein the optical signal further comprises an optical qubit distributed over the N transmission channels as a coherent linear superposition of states.

5. The distribution system of claim 1 wherein the transmission channels are optical fibers.

6. The distribution system of claim 1 wherein the distributed signal further comprises an optical signal comprising a coherent linear superposition of states.

7. The distribution system of claim 1 wherein the detectors are non-demolition detectors.

8. A system for circumventing a transmission-channel disruption and alerting transmission-channel users of the transmission-channel disruption, the system comprising: an input for receiving a first signal encoding information;N−1 multiplexing beamsplitters for splitting the first signal into N distributed signals;N transmission channels, each transmission channel carrying one of the N distributed signals;N−1 demultiplexing beamsplitters for combining the N distributed signals into a second signal that encodes the information;a first detector for detecting the second signal output from the N−1 demultiplexing beamsplitters; andone or more detectors for detecting a third signal output from the N−1 demultiplexing beamsplitters when a disruption occurs in one or more of the N transmission channels, the third signal alerts the transmission-channel users of the disruption.

9. The system of claim 8 wherein the first signal further comprises electromagnetic waves encoding information in one of: amplitude of the electromagnetic wave;phase of the electromagnetic wave; andfrequency of the electromagnetic wave.

10. The system of claim 8 wherein the first signal further comprises one or more qubits.

11. The system of claim 8 wherein the N−1 multiplexing beamsplitters are mathematically represented by:

12. The system of claim 8 wherein the N−1 demultiplexing beamsplitters are mathematically represented by:

13. A method for alerting transmission-channel users of a disruption in one or more transmission channels, the method comprising: producing a first signal that encodes information;multiplexing the first signal by distributing the first signal over N transmission channels to obtain N distributed signals;demultiplexing the N distributed signals by combining the N distributed signals into a second signal that encodes the information;detecting the second signal at a first detector; anddetecting a third signal at a second detector when a disruption occurs in one or more of the N transmission channels, the third signal alerts the transmission-channel users of the disruption.

14. The method of claim 13 wherein producing the first signal further comprises encoding information in an electromagnetic wave by one of: modulating the amplitude of the electromagnetic wave;modulating the phase of the electromagnetic wave; andmodulating the frequency of the electromagnetic wave.

15. The method of claim 13 wherein producing the first signal further comprises encoding information in one or more qubits.

16. The method of claim 13 wherein multiplexing the first signal further comprises transmitting the first signal to a multiplexer comprising N−1 beamsplitters mathematically represented by:

17. The method of claim 13 wherein demultiplexing the distributed signals further comprises transmitting the signals distributed in N transmission channels to a demultiplexer comprising N−1 beamsplitters mathematically represented by: