Spectrally multiplexed single-photon emitter

A method comprising:

• selecting, based on a received heralding signal, at least one pump field from a plurality of pump fields having a plurality of pump frequencies;
• and
• causing, based on the selected at least one pump field, a pump field selector to permit the selected at least one pump field to be incident on a non-linear photonic element;
• wherein the received heralding signal is representative of a detection of a first photon of a frequency-correlated photon pair, the received heralding signal indicative of a frequency of a heralded second photon of the frequency-correlated photon pair;
• wherein the non-linear photonic element is configured to receive the heralded second photon and to produce an output photon having a predefined frequency based on the frequency of the heralded second photon and a pump frequency of the selected at least one pump field;
• and
• wherein:
• the non-linear photonic element has different conversion efficiencies for different frequencies of heralded second photons;
• and
• in the event of a contemporaneous detection of two first photons of two frequency-correlated photon pairs, the two first photons having different frequencies, selecting the at least one pump field is further based on the conversion efficiencies of the non-linear photonic element.

A controller configured to:

• select, based on a received heralding signal, at least one pump field from a plurality of pump fields having a plurality of pump frequencies;
• and
• cause, based on the selected at least one pump field, a pump field selector to permit the selected at least one pump field to be incident on a non-linear photonic element;
• wherein the received heralding signal is representative of a detection of a first photon of a frequency-correlated photon pair, the received heralding signal indicative of a frequency of a heralded second photon of the frequency-correlated photon pair;
• wherein the non-linear photonic element is configured to receive the heralded second photon and to produce an output photon having a predefined frequency based on the frequency of the heralded second photon and a pump frequency of the selected at least one pump field;
• and
• wherein:
• the non-linear photonic element has different conversion efficiencies for different frequencies of heralded second photons;
• and
• in the event of a contemporaneous detection of two first photons of two frequency-correlated photon pairs, the two first photons having different frequencies, the controller is configured to select the at least one pump field based further on the conversion efficiencies of the non-linear photonic element.

A non-transitory computer-readable storage medium having stored thereon a computer-readable circuit description of a controller configured to:

• select, based on a received heralding signal, at least one pump field from a plurality of pump fields having a plurality of pump frequencies;
• and
• cause, based on the selected at least one pump field, a pump field selector to permit the selected at least one pump field to be incident on a non-linear photonic element;
• wherein the received heralding signal is representative of a detection of a first photon of a frequency-correlated photon pair, the received heralding signal indicative of a frequency of a heralded second photon of the frequency-correlated photon pair;
• wherein the non-linear photonic element is configured to receive the heralded second photon and to produce an output photon having a predefined frequency based on the frequency of the heralded second photon and a pump frequency of the selected at least one pump field;
• wherein the computer-readable circuit description, when processed in a controller generation system, causes the controller to manufacture or otherwise generate an implementation of the controller;
• and
• wherein:
• the non-linear photonic element has different conversion efficiencies for different frequencies of heralded second photons;
• and
• in the event of a contemporaneous detection of two first photons of two frequency-correlated photon pairs, the two first photons having different frequencies, the controller is configured to select the at least one pump field based further on the conversion efficiencies of the non-linear photonic element.