Abstract: An optical device comprising: a light routing element coupled to a first optical path and a second optical path such that light received by the light routing element is directed into one of the first optical path or the second optical path; a combiner coupling the first optical path and second optical path into a single output path; a controller applying a control signal to said light routing element, the control signal indicating whether a portion of the light received by the light routing element is directed into the first optical path or into the second optical path; a phase controlling element provided in the first optical path such that there is provided a pre-determined fixed phase difference between a light pulse routed through the first optical path and a light pulse routed through the second optical path.

Abstract: An optical device for a quantum random number generator comprising: a source of phase randomised pulses of light, the source of phase randomised pulses of light further comprising a plurality of gain-switched lasers, each gain-switched laser having an output, and each gain-switched laser being configured to emit a stream of pulses such that the phase of each pulse in the stream of pulses is randomised, and an optical pulse combiner, the optical pulse combiner being configured to receive streams of pulses from the output of each gain-switched laser, combine the streams of pulses with one another into a combined stream of pulses and direct the combined stream of pulses into at least one output of the optical pulse combiner, the at least one output of the optical pulse combiner being the output of the source of phase randomised pulses of light; wherein the source of phase randomised pulses of light is configured such that the streams of pulses of light emitted by the plurality of gain-switched lasers are tem

Abstract: An optical module includes: a quantum photonic integrated circuit; a temperature controller; and a housing configured to house the photonic integrated circuit and the temperature controller. The photonic integrated circuit is attached to the temperature controller, such that the photonic integrated circuit is in thermal communication with the temperature controller, and the temperature controller is attached directly to the housing, such that the temperature controller is in direct thermal communication with the housing.

Abstract: An optical device includes a first semiconductor substrate, a reference laser configured to generate coherent light, a plurality of first optical components, a plurality of second optical components, one or more first controllers configured to apply phase control signals to said plurality of first optical components to apply a phase shift, and one or more second controllers configured to apply pulse control signals to said plurality of second optical components such that a light pulse is outputted during a period of time that coherent light is received. The relative phase between emitted light pulses from the plurality of second optical components is controlled by the relative phase shifts applied by the one or more first controllers.

Abstract: An optical module includes: a quantum photonic integrated circuit; a temperature controller; and a housing configured to house the photonic integrated circuit and the temperature controller. The photonic integrated circuit is attached to the temperature controller, such that the photonic integrated circuit is in thermal communication with the temperature controller, and the temperature controller is attached directly to the housing, such that the temperature controller is in direct thermal communication with the housing.

Abstract: A system for generating a biased random bit stream, wherein said biased bit stream has different predetermined probabilities of occurrence for bit “0” and bit “1”, said system comprising: a true random generator unit configured to output a true random bit stream, a pseudo random generator unit configured to output a pseudo random bit stream, said pseudo random bit stream comprising n bit words, where n is an integer of at least two; a combining unit configured to combine a bit from said true random generator unit with an n-bit word from said pseudo random generator unit to output a processed n-bit word; and an output unit configured to generate an output bit value from said processed n-bit word using a function, wherein said function is selected to control the probabilities of occurrence of the bit “0” values and bit “1” values to be the predetermined probabilities of occurrence.

Abstract: A transmitter for a quantum communication system, comprising: a photon source unit comprising a photon source; a first intensity modulator, configured to receive an input light pulse from the photon source unit, the first intensity modulator comprising: a first element, configured to split the input light pulse into two components; a phase modulator, configured to apply a phase shift between the two components; and a second element, configured to interfere the two components; wherein at least one of the first element and the second element is asymmetric.

Abstract: An optical device for a quantum random number generator comprising: a source of phase randomised pulses of light, the source of phase randomised pulses of light further comprising a plurality of gain-switched lasers, each gain-switched laser having an output, and each gain-switched laser being configured to emit a stream of pulses such that the phase of each pulse in the stream of pulses is randomised, and an optical pulse combiner, the optical pulse combiner being configured to receive streams of pulses from the output of each gain-switched laser, combine the streams of pulses with one another into a combined stream of pulses and direct the combined stream of pulses into at least one output of the optical pulse combiner, the at least one output of the optical pulse combiner being the output of the source of phase randomised pulses of light; wherein the source of phase randomised pulses of light is configured such that the streams of pulses of light emitted by the plurality of gain-switched lasers are tem

Abstract: An optical device, comprising: a first semiconductor substrate; a reference laser, configured to generate coherent light; a plurality of first optical components, wherein the reference laser is optically coupled to the plurality of first optical components, wherein each of the plurality of first optical components is configured to output coherent light during a period of time that coherent light from the reference laser is received; a plurality of second optical components, the second optical components configured to produce optical intensity modulation, wherein each of the plurality of first optical components is optically coupled to at least one corresponding second optical component; wherein the plurality of first optical components each comprises a laser, an optical amplifier or a phase modulator, and the plurality of second optical components each comprises a laser, an optical amplifier or an intensity modulator, and wherein when a first optical component comprises a laser or an optical amplifier the

Abstract: A transmitter for a quantum communication system, comprising: a photon source unit comprising a photon source; a first intensity modulator, configured to receive an input light pulse from the photon source unit, the first intensity modulator comprising: a first element, configured to split the input light pulse into two components; a phase modulator, configured to apply a phase shift between the two components; and a second element, configured to interfere the two components; wherein at least one of the first element and the second element is asymmetric.

Abstract: A component for a quantum communication system, the component comprising: an input section and a decoder section, the input section comprising n waveguides, where n is an integer of at least 2, the decoder section comprising m decoders, where m is an integer of at least 2, each decoder comprising at least one waveguide, the input section and the decoder section being provided on a single substrate such that the waveguides are continuous and integrated between the input section and the decoder section, the waveguides of the input section and the decoder section being arranged such that light pulses enter the waveguides of the decoder section via the waveguides of the input section and the m decoders operate in parallel.

Abstract: A component for a quantum communication system, the component comprising: an input section and a decoder section, the input section comprising n waveguides, where n is an integer of at least 2, the decoder section comprising m decoders, where m is an integer of at least 2, each decoder comprising at least one waveguide, the input section and the decoder section being provided on a single substrate such that the waveguides are continuous and integrated between the input section and the decoder section, the waveguides of the input section and the decoder section being arranged such that light pulses enter the waveguides of the decoder section via the waveguides of the input section and the m decoders operate in parallel.

Abstract: An all-optical spin device is based on spin multistability of trapped microactivity polaritons.