Bandwidth provisioning for an entangled photon system
A quantum key distribution system is deployed in an optical fiber network transporting classical data traffic. A source of entangled photon pairs is used to generate quantum keys. Classical data traffic is typically transported over channels in the C-band. If a pair of channels for transport of quantum data is available within the C-band, then the source of entangled photon pairs is tuned to emit in a pair of channels in the C-band. If a pair of channels for transport of quantum data is not available within the C-band, then the source of entangled photon pairs is tuned to emit in a pair of channels in a combined S-band and L-band. When a periodically-poled lithium niobate waveguide pumped with a laser is used for the source of entangled photon pairs, the output spectral properties are tuned by varying the temperature of the waveguide.
1. A method for provisioning bandwidth for quantum data transport in an optical fiber network comprising a wavelength selective switch having an input port, a first output port, and a second output port, wherein the input port receives a first optical beam from a first optical source and a second optical beam from a second optical source, the method comprising:
monitoring data traffic transmitted from the second optical source in a first frequency band;
upon determining that a pair of channels for quantum data transport is available in the first frequency band:
transmitting from the first optical source a pair of entangled photons in a first pair of channels in the first frequency band; and
upon determining that a pair of channels for quantum data transport is not available in the first frequency band:
transmitting from the first optical source a pair of entangled photons in a second pair of channels in a second frequency band and a third frequency band.
2. The method of claim 1 , wherein:
the first frequency band is the telecommunications C-band;
the second frequency band is the telecommunications S-band; and
the third frequency band is the telecommunications L-band.
3. The method of claim 2 , wherein the first optical source comprises a periodically-poled lithium niobate waveguide.
4. The method of claim 3 , wherein transmitting from the first optical source a pair of entangled photons in a first pair of channels in the first frequency band comprises:
adjusting the temperature of the periodically-poled lithium niobate waveguide to a first temperature.
5. The method of claim 4 , wherein the first temperature is approximately 56 degrees Celsius.
6. The method of claim 3 , wherein transmitting from the first optical source a pair of entangled photons in a second pair of channels in a second frequency band and a third frequency band comprises:
adjusting the temperature of the periodically-poled lithium niobate waveguide to a second temperature.
7. The method of claim 6 , wherein the second temperature is approximately 60 degrees Celsius.
8. An apparatus for provisioning bandwidth for quantum data transport in an optical fiber network comprising a wavelength selective switch having an input port, a first output port, and a second output port, a first optical source configured to transmit a first optical beam into the input port, and a second optical source configured to transmit a second optical beam into the input port, the apparatus comprising:
means for monitoring data traffic transmitted by the second optical source in a first frequency band;
means for:
upon determining that a pair of channels for quantum data transport is available in the first frequency band:
transmitting from the first optical source a pair of entangled photons in a first pair of channels in the first frequency band; and
means for:
upon determining that a pair of channels for quantum data transport is not available in the first frequency band:
transmitting from the first optical source a pair of entangled photons in a second pair of channels in a second frequency band and a third frequency band.
9. The apparatus of claim 8 , wherein:
the first frequency band is the telecommunications C-band;
the second frequency band is the telecommunications S-band; and
the third frequency band is the telecommunications L-band.
10. The apparatus of claim 9 , wherein the first optical source comprises a periodically-poled lithium niobate waveguide.
11. The apparatus of claim 10 , wherein the means for transmitting from the first optical source a pair of entangled photons in a first pair of channels in the first frequency band comprises:
means for adjusting the temperature of the periodically-poled lithium niobate waveguide to a first temperature.
12. The apparatus of claim 11 , wherein the first temperature is approximately 56 degrees Celsius.
13. The apparatus of claim 10 , wherein the means for transmitting from the first optical source a pair of entangled photons in a second pair of channels in a second frequency band and a third frequency band comprises:
means for adjusting the temperature of the periodically-poled lithium niobate waveguide to a second temperature.
14. The apparatus of claim 13 , wherein the second temperature is approximately 60 degrees Celsius.
15. A computer readable medium storing computer program instructions for provisioning bandwidth for quantum data transport in an optical fiber network comprising a wavelength selective switch having an input port, a first output port, and a second output port, wherein the input port receives a first optical beam from a first optical source and a second optical beam from a second optical source, the computer program instructions defining:
monitoring data traffic transmitted from the second optical source in a first frequency band;
upon determining that a pair of channels for quantum data transport is available in the first frequency band:
transmitting from the first optical source a pair of entangled photons in a first pair of channels in the first frequency band; and
upon determining that a pair of channels for quantum data transport is not available in the first frequency band:
transmitting from the first optical source a pair of entangled photons in a second pair of channels in a second frequency band and a third frequency band.
16. The computer readable medium of claim 15 , wherein:
the first frequency band is the telecommunications C-band;
the second frequency band is the telecommunications S-band; and
the third frequency band is the telecommunications L-band.
17. The computer readable medium of claim 16 , wherein the first optical source comprises a periodically-poled lithium niobate waveguide.
18. The computer readable medium of claim 17 , wherein the computer program instructions defining transmitting from the first optical source a pair of entangled photons in a first pair of channels in the first frequency band comprises computer program instructions defining:
adjusting the temperature of the periodically-poled lithium niobate waveguide to a first temperature.
19. The computer readable medium of claim 17 , wherein the computer program instructions defining transmitting from the first optical source a pair of entangled photons in a second pair of channels in a second frequency band and a third frequency band comprises computer program instructions defining:
adjusting the temperature of the periodically-poled lithium niobate waveguide to a second temperature.