Abstract: An apparatus has a plurality of photonic elements. At least two photonic elements forming a cavity. At least one photonic element receives first electromagnetic radiation from outside the cavity and transmits the first electromagnetic radiation into the photonic cavity. At least one photonic element receives second electromagnetic radiation from outside the cavity and transmits the second radiation into the photonic cavity. A photonic memory disposed in the cavity comprises an atomic system that: receives a photon field of first radiation; receives second radiation; stores at least a portion of the field of the photon in the atomic system via an atomic transition using the photon and the received second radiation; emits the stored portion of the photon upon receiving third electromagnetic radiation. The apparatus directs the photon into the photonic memory, after being reflected into the photonic cavity by at least one of the photonic elements; and outputs the emitted portion of the field into the cavity.

Abstract: An apparatus has a plurality of photonic elements. At least two photonic elements forming a cavity. At least one photonic element receives first electromagnetic radiation from outside the cavity and transmits the first electromagnetic radiation into the photonic cavity. At least one photonic element receives second electromagnetic radiation from outside the cavity and transmits the second radiation into the photonic cavity. A photonic memory disposed in the cavity comprises an atomic system that: receives a photon field of first radiation; receives second radiation; stores at least a portion of the field of the photon in the atomic system via an atomic transition using the photon and the received second radiation; emits the stored portion of the photon upon receiving third electromagnetic radiation. The apparatus directs the photon into the photonic memory, after being reflected into the photonic cavity by at least one of the photonic elements; and outputs the emitted portion of the field into the cavity.

Abstract: An apparatus is disclosed herein. The apparatus comprises a non-linear photonic element for outputting a signal and idler photon pair. The apparatus further comprises a module configured to, based on receiving one or more control signals, controllably store photons and controllably output stored photons. The apparatus further comprises a detector arrangement comprising one or more detectors for detecting light. The module is further configured to receive at least one of the signal and idler photons of the pair. The module is further configured to at least partially store one of the signal or idler photons of the pair. The module is further configured to output the said at least partially stored signal or idler photon along an optical path towards the at least one detectors. The apparatus is configured to direct the other of the signal or idler photon towards the detector arrangement.

Abstract: A method (300) for generating random numbers including: mixing (304) a bright quantum state in a first mode with a vacuum input (15), in a two mode transformation for mixing the first mode and an orthogonal second mode; after mixing, detecting (306) the intensity in the first mode, and the second mode; generating random numbers (312) based on the difference between the detected intensity of the first mode and the second mode; and simultaneously to generating random numbers, certifying the numbers as random, based on the sum of the detected intensity of the first mode and the second mode, wherein certifying confirms that the process by which the random numbers are generated is quantum in origin and so the numbers are random.

Abstract: A de-multiplexer (1) for separating two co-propagating modes of electromagnetic radiation includes a volume (2) having a path therethrough for receiving electromagnetic radiation, an input (8) for directing two co-propagating modes of electromagnetic radiation to be incident upon the volume, a control source (12) of electromagnetic radiation arranged to generate a time-dependent control field. The volume is arranged and the time-dependent control field is shaped such that, when the two co-propagating modes of electromagnetic radiation and the time-dependent control field are incident upon the volume contemporaneously, the time-dependent control field causes the volume to accept one of the two modes of electromagnetic radiation onto a mode of the volume without any parametric non-linear optical interaction taking place and to reflect or transmit the other of the two modes of electromagnetic radiation, so to spatially and/or temporally separate the two modes of electromagnetic radiation from each other.

Abstract: A de-multiplexer (1) for separating two co-propagating modes of electromagnetic radiation includes a volume (2) having a path therethrough for receiving electromagnetic radiation, an input (8) for directing two co-propagating modes of electromagnetic radiation to be incident upon the volume, a control source (12) of electromagnetic radiation arranged to generate a time-dependent control field. The volume is arranged and the time-dependent control field is shaped such that, when the two co-propagating modes of electromagnetic radiation and the time-dependent control field are incident upon the volume contemporaneously, the time-dependent control field causes the volume to accept one of the two modes of electromagnetic radiation onto a mode of the volume without any parametric non-linear optical interaction taking place and to reflect or transmit the other of the two modes of electromagnetic radiation, so to spatially and/or temporally separate the two modes of electromagnetic radiation from each other.

Abstract: A quantum memory device includes an atomic ensemble (4) and a signal source of electromagnetic radiation (10) for generating modes to be stored and having a frequency corresponding to an off-resonant transition between first and second states in the atomic ensemble. The quantum memory device also includes a control source of electromagnetic radiation (12) for generating electromagnetic radiation having a frequency corresponding to an off-resonant atomic transition between second and third states in the atomic ensemble; the third state has a higher energy than the second state which has a higher energy than the first state. The signal source and the control source create a coherent excitation of the transition between the first state and the third state such that the atomic ensemble stores the signal source modes, and the control source subsequently stimulates emission of the stored modes from the atomic ensemble.

Abstract: A method (300) for generating random numbers including: mixing (304) a bright quantum state in a first mode with a vacuum input (15), in a two mode transformation for mixing the first mode and an orthogonal second mode; after mixing, detecting (306) the intensity in the first mode, and the second mode; generating random numbers (312) based on the difference between the detected intensity of the first mode and the second mode; and simultaneously to generating random numbers, certifying the numbers as random, based on the sum of the detected intensity of the first mode and the second mode, wherein certifying confirms that the process by which the random numbers are generated is quantum in origin and so the numbers are random.

Abstract: A quantum memory device includes an atomic ensemble (4) and a signal source of electromagnetic radiation (10) for generating modes to be stored and having a frequency corresponding to an off-resonant transition between first and second states in the atomic ensemble. The quantum memory device also includes a control source of electromagnetic radiation (12) for generating electromagnetic radiation having a frequency corresponding to an off-resonant atomic transition between second and third states in the atomic ensemble; the third state has a higher energy than the second state which has a higher energy than the first state. The signal source and the control source create a coherent excitation of the transition between the first state and the third state such that the atomic ensemble stores the signal source modes, and the control source subsequently stimulates emission of the stored modes from the atomic ensemble.

Abstract: An electromagnetic frequency converter includes an atomic ensemble; one or more first sources (6, 8) of electromagnetic radiation (P, R) to be incident upon the atomic ensemble to excite atomic valence electrons from a ground state to a first Rydberg state; one or more second sources (6, 14) of electromagnetic radiation (A, C) to be incident upon the atomic ensemble to excite atomic valence electrons from an excited state to a second Rydberg state; a first input (20) and/or output (26) for electromagnetic radiation (L) to be incident upon the atomic ensemble from the first input or received from the atomic ensemble at the first output; and a second input (14) and/or output (24) for electromagnetic radiation (M) to be incident upon the atomic ensemble from the second input or received from the atomic ensemble at the second output.

Abstract: An electromagnetic frequency converter includes an atomic ensemble; one or more first sources (6, 8) of electromagnetic radiation (P, R) to be incident upon the atomic ensemble to excite atomic valence electrons from a ground state to a first Rydberg state; one or more second sources (6, 14) of electromagnetic radiation (A, C) to be incident upon the atomic ensemble to excite atomic valence electrons from an excited state to a second Rydberg state; a first input (20) and/or output (26) for electromagnetic radiation (L) to be incident upon the atomic ensemble from the first input or received from the atomic ensemble at the first output; and a second input (14) and/or output (24) for electromagnetic radiation (M) to be incident upon the atomic ensemble from the second input or received from the atomic ensemble at the second output.