Patent application number | Description | Published |
20100111305 | PHOTON DETECTOR - A photon detection system including a photon detector configured to detect single photons, a signal divider to divide the output signal of the photon detector into a first part and a second part, wherein the first part is substantially identical to the second part, a delay mechanism to delay the second part with respect to the first part, and a combiner to combine the first and delayed second parts of the signal such that the delayed second part is used to cancel periodic variations in the first part of the output signal. | 05-06-2010 |
20100157310 | OPTICAL SYSTEM FOR CREATING INTERFERENCE BETWEEN PHOTONS - An optical system including: a photon source; first directing elements configured to direct photons to follow a first path through the optical system; second directing elements configured to direct photons to follow a second path through the optical system, wherein the second path is the reverse of the first path, photons travelling through the first path having a different polarization to those travelling through the second path; and a mechanism varying the relative phase shift between photons following the first path and photons following the second path. | 06-24-2010 |
20100232279 | OPTICAL RETRIEVAL SYSTEM, DATA STORAGE SYSTEM, DATA STORAGE MEDIUM AND METHOD OF OPTICAL RETRIEVAL AND DATA STORAGE - An optical data retrieval system configured to retrieve data from a data storage medium, including: a source of n path-entangled photons, where n is an integer of at least 2; a detector system configured to determine if n photons have been received; and a mechanism to direct photons from the source to the data storage medium and to the detector system. | 09-16-2010 |
20100294919 | PHOTON DETECTION SYSTEM AND METHOD OF PHOTON DETECTION - According to one embodiment, a photon detection system determines the number of detected photons. The detection system includes an avalanche photodiode and a measuring unit. The measuring unit measures an avalanche signal induced by illumination before the avalanche current through the device has saturated. | 11-25-2010 |
20110013906 | QUANTUM INFORMATION SYSTEM - According to one embodiment, a quantum information system includes a source of time dependent entangled photons and an indicating unit. The indicating unit indicates the entangled state of the entangled photons based on the emission time of one or more of the entangled photons. | 01-20-2011 |
20120168612 | PHOTON DETECTION SYSTEM AND METHOD OF PHOTON DETECTION - According to one embodiment, a photon detection system determines the number of detected photons. The detection system includes an avalanche photodiode and a measuring unit. The measuring unit measures an avalanche signal induced by illumination before the avalanche current through the device has saturated. | 07-05-2012 |
20120326116 | SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING A SEMICONDUCTOR DEVICE - A semiconductor structure with a waveguide, the semiconductor structure has a plurality of layers, at least one of which being partially laterally oxidised, said laterally oxidised material modifying the lateral effective refractive index with said structure in order to form a waveguide within the structure, the structure also has a quantum dot, said quantum dot being configured to emit photons into said waveguide, the waveguide being configured such that it guides the output from a single quantum dot. | 12-27-2012 |
20130214134 | PHOTON DETECTOR - A photon detection system comprising an avalanche photo-diode, said avalanche photodiode comprising a p-n junction formed from a first semiconductor layer having a first conductivity type and a second semiconductor layer having a second conductivity type, wherein the first conductivity type is one selected from n-type or p-type and the second conductivity type is different to the first conductivity type and is selected from n-type or p-type, wherein the first semiconductor layer is a doped layer which is doped with dopants of a first conductivity type and where there is a variation in the concentration of dopants of the first conductivity type such that the first layer comprises islands of high field zones surrounded by low field zones, the high and low field zones distributed laterally in the plane of the p-n junction, wherein the dopant concentration is higher in the high field zones than the low field zones, said system further comprising a biasing unit, said biasing unit being configured to apply a voltage which is static in time and a time varying voltage. | 08-22-2013 |
20150304051 | OPTICAL DEVICE - An optical device, comprising an optical component, configured to produce optical amplification; a component configured to intermittently supply coherent light to said optical component; and a controller, configured to apply a time varying signal to said optical component such that a plurality of light pulses are emitted during each period of time that said coherent light is received, wherein the plurality of light pulses emitted during each period have a fixed phase relation. | 10-22-2015 |
Patent application number | Description | Published |
20100027794 | QUANTUM COMMUNICATION SYSTEM - A system for transmitting quantum information comprising a sending unit and a receiving unit,
| 02-04-2010 |
20110108712 | PHOTON DETECTOR - A photon detection system comprising an avalanche photodiode and a voltage source for said avalanche photodiode, wherein said avalanche photodiode comprises Silicon or its heterostructures and wherein said voltage source is configured to bias said avalanche photodiode with a voltage component which is static with respect to time and a voltage component which varies with time. | 05-12-2011 |
20110108743 | TUNEABLE QUANTUM LIGHT SOURCE - A photon source comprising a semiconductor heterostructure, said semiconductor heterostructure comprising a quantum well, a barrier region adjacent said quantum well and a quantum dot provided in said quantum well, the photon source further comprising electrical contacts and a power supply coupled to first and second electrical contacts configured to apply a tuneable electric field across said quantum dot to control the emission energy of said quantum dot, said electric field being tuneable across an operating range an wherein the tunnelling time of carriers from said quantum dot to said first electrical contact and the tunnelling time of carriers from said quantum dot to said second electrical contact are greater than the radiative decay time of an exciton in said quantum dot over said operating range for controlling the emission energy, said photon source being configured such that emission from a single quantum dot exits said photon source. | 05-12-2011 |
20110108744 | PHOTON SOURCE FOR PRODUCING ENTANGLED PHOTONS - A photon source comprising: a quantum dot; electrical contacts configured to apply an electric field across said quantum dot: and an electrical source coupled to said contacts, said electrical source being configured to apply a potential such that carriers are supplied to said quantum dot to form a bi-exciton or higher order exciton, wherein said photon source further comprises a barrier configured to increase the time which a carrier takes to tunnel to and from said quantum dot to be greater than the radiative lifetime of an exciton in the quantum dot, the quantum dot being suitable for emission of entangled photons during decay of a bi-exciton or higher order exciton. | 05-12-2011 |
20110149364 | OPTICAL DEVICE AND METHOD FOR ITS MANUFACTURE - An optical device which can operate as a single photon emitter | 06-23-2011 |
20110173696 | QUANTUM COMMUNICATION SYSTEM AND METHOD - A quantum communication system, said system comprising:
| 07-14-2011 |
20110242632 | QUANTUM LOGIC COMPONENT AND A METHOD OF CONTROLLING A QUBIT - A component comprising a qubit and a controller for said qubit, said component comprising a quantum dot and an excitation portion configured to produce a neutral exciton state in said quantum dot to form said qubit, the component further comprising a measuring unit to make an optical measurement relating to the orientation of said state, wherein said controller comprises voltage source coupled to electrical contacts configured to apply a modulated electric field across said quantum dot, wherein the modulation is faster than the decay time of said neutral exciton state. | 10-06-2011 |
20110272671 | SEMICONDUCTOR DEVICE AND A METHOD OF FABRICATING A SEMICONDUCTOR DEVICE - A semiconductor device comprising a quantum dot and a plurality of layers, wherein said plurality of layers comprises: a first layer; a stressor layer; and a patterned layer wherein said stressor layer overlies said first layer and said patterned layer overlies said stressor layer; wherein said stressor layer has a substantially different lattice constant to said first layer and said patterned layer and has a pit provided in said layer; said quantum dot lying above said patterned layer aligned with said pit. | 11-10-2011 |
20120063789 | PHOTON DETECTOR - A photon detection system comprising: an avalanche photodiode; a biasing circuit configured to reverse bias said avalanche photodiode; a first measuring circuit configured to measure avalanche events occurring in said avalanche photodiode as a transient current due to photon absorption; and a second measuring circuit configured to measure the bias current flowing through the avalanche photodiode. | 03-15-2012 |
20120177374 | QUANTUM COMMUNICATION SYSTEM - A quantum communication system including a sending unit and a receiving unit, said sending unit comprising a photon source assembly configured to output a stream of pulses of light having at least two different intensities and a memory configured to store information for determining which pulses should be reference pulses and which pulses should be data pulses, the average intensity of reference pulses being different to the average intensity of data pulses, the receiving unit comprising a memory for storing information for identifying the position of reference pulses within the stream of pulses and a processor for determining the calibration of the quantum communication system from the reference pulses. | 07-12-2012 |
20120230702 | PHOTON DETECTOR - A photon detection system including a photon detector configured to detect single photons, the photon detector being gated such that it produces a periodic output signal and the gating signal having a frequency of at least 50 MHz. The system further includes a combiner for combining the signal from one period with signals from other periods such that periodic variations in the output signal of the detector are suppressed. | 09-13-2012 |
20120292590 | OPTICAL COMPONENT - An optical component comprising an emitter and a solid reflector, said reflector having a convex outer surface, said emitter being located within the solid reflector, the emitter being configured to emit radiation via an electric dipole transition, the dipole having a dipole axis being orientated at an angle of 45 degrees or less to the surface normal at the apex of the reflector. | 11-22-2012 |
20120294625 | COMMUNICATION SYSTEM AND METHOD - A communication system comprising an emitter of weak light pulses, a detector which is capable of detecting single photons, and a source of a clock signal, wherein said emitter and detector are synchronised using said clock signal, the system further comprising a frequency divider for said clock signal to produce a reduced frequency clock signal and a clock regenerator for regenerating the original clock signal from the reduced frequency clock signal, the system further comprising a communication channel configured to communicate the clock signal between the emitter and detector, the clock signal being reduced before sending through said channel and reconstructed after it has exited said channel. | 11-22-2012 |
20120326624 | PHOTON SOURCE - A photon source comprising a photon source body, said photon source body comprising at least one quantum dot; carrier injection means for injecting carriers into said at least one quantum dot and change of state means for changing the state of the carriers within the quantum dot after a predetermined time duration, the carrier injection means injecting carriers which are configured to allow emission of radiation by radiative recombination | 12-27-2012 |
20120328290 | QUANTUM COMMUNICATION NETWORK - A quantum communication system comprising a receiver and a plurality of transmitters, said receiver comprising a detector sub-system, each of said transmitters being configured to emit pulses of radiation, said detector subsystem comprising at least one detector, said detector being configured to detect said light pulses, the system comprising a timing control module, said timing control module being configured to control the number of light pulses received by the detector sub-system, such that just one light pulse from one transmitter reaches the detector sub-system at any one time, the timing control module also allowing the transmitter which sent said pulse to be identified. | 12-27-2012 |
20130107617 | QUANTUM MEMORY | 05-02-2013 |
20130256504 | PHOTON SOURCE - An optical device comprising a quantum dot provided in a resonant confinement structure, an output from said confinement structure and a pulsed excitation source for said quantum dot, wherein the quantum dot is configured to allow the emission of photons having a first energy in response to a pulse from said excitation source, said resonant confinement structure providing optical confinement, the first energy being different to the resonant energy of the resonant confinement structure, the optical device further comprising a timing unit, said timing unit being configured to select photons which have been emitted from the quantum dot due to excitation by a pulse, the timing unit selecting photons emitted after the duration of the pulse which caused the emission of the photons. | 10-03-2013 |
20130322873 | SYSTEM AND METHOD FOR QUANTUM TELEPORTATION - A system for quantum teleportation of a quantum state of an input photon, including: a light emitting diode configured to produce a polarization entangled photon pair; a beam splitter configured to direct photons of the entangled photon pair along respective first and second paths; a measurement unit performing a joint measurement on the input photon; a timing unit configured to measure a first delay between the input photon and the photon of the entangled photon pair at a point of maximum indistinguishability of the photons as they pass through the joint measurement unit, and to measure a second delay between the two photons of the entangled photon pair as they exit the light emitting diode; a controller configured to determine a teleportation measurement is valid if the first delay is within a first predetermined timing window and the second delay is within a second predetermined timing window. | 12-05-2013 |
20140105598 | SYSTEM AND METHOD FOR INTENSITY MONITORING - A detection system for monitoring the intensity of a stream of modulated pulses, the system comprising a controller configured to provide a control signal to a component outputting modulated pulses the control signal controlling the level of modulation for each pulse exiting the component and a detector configured to measure the intensity of the pulses in the stream of pulses exiting the component outputting modulated pulses, wherein the detector comprises a gated detector, the controller being configured to send a gating signal to said detector, wherein said gating signal varies the gain of the detector with the control signal, such that pulses with a selected modulation level can be detected. | 04-17-2014 |
20140205301 | MODULATION UNIT - A modulation unit for a quantum communication system, wherein said modulation unit comprises an optical component configured to cause a delay between photons with different polarisation modes and a phase modulator, the optical component comprising a birefringent optical material, wherein the birefringent optical material supports the transmission of photons with a first polarisation mode and a second polarisation mode, wherein the optical path length for photons propagating with the first polarisation mode is different to the optical path length of photons propagating with the second polarisation mode, photons with the first polarisation mode having an orthogonal polarisation to those with the second polarisation mode, the phase modulator being configured to apply a further phase difference between photons with the first and second polarisation mode which pass through said modulation unit. | 07-24-2014 |
20140321862 | PHOTON DETECTOR AND A PHOTON DETECTION METHOD - A photon detection system is provided comprising a photon detector, configured to detect photons during intervals when in a receiving state and to output a signal when a photon is received, a controller, configured to generate a time varying gating signal wherein said gating signal switches said detector between the receiving state and a non-receiving state, said controller being configured to receive and process information relating to the times photons are expected to arrive at said detector, the controller being configured to generate the gating signal such that the photon detector is in the receiving state for intervals when photons are expected and also in the receiving state for additional intervals between the intervals when the photons are expected; a detection module, configured to distinguish between when the output signal from the photon detector corresponds to an interval when photons are expected and said additional intervals. | 10-30-2014 |
20140341575 | SIGNAL MANIPULATOR FOR A QUANTUM COMMUNICATION SYSTEM - A signal manipulator, comprising:
| 11-20-2014 |
20150034808 | PHOTON DETECTOR - A photon detection system including a photon detector configured to detect single photons, a signal divider to divide the output signal of the photon detector into a first part and a second part, wherein the first part is substantially identical to the second part, a delay mechanism to delay the second part with respect to the first part, and a combiner to combine the first and delayed second parts of the signal such that the delayed second part is used to cancel periodic variations in the first part of the output signal. | 02-05-2015 |
20150331672 | RANDOM NUMBER GENERATOR - A random number generation system, comprising: a light source configured to generate light pulses and a driving unit configured to drive said light source such that the phase of each light pulse has a random relationship to the phase of each subsequently generated light pulse, and such that each light pulse is generated with at least two local maxima in the temporal intensity profile. | 11-19-2015 |
20150333840 | PHOTON SOURCE - A photon source comprising a quantum structure capable of defining one or more quantum levels such that a photon may be emitted from the quantum structure due to a transition between at least two quantum levels,
| 11-19-2015 |
20150372768 | QUANTUM COMMUNICATION SYSTEM - A transmitter for a quantum communication system, the transmitter comprising an interferometer, the interferometer having a first path with a phase modulator and a second path configured such that light pulses entering the interferometer follow either the first path or the second path, the output of the first and second paths being combined, the transmitter further comprising an optical filter positioned such that photons exiting the interferometer pass through the optical filter, the optical filter being configured to restrict the frequency range of pulses passing through the optical filter and temporally broaden the pulses. | 12-24-2015 |
20160047643 | INTERFERENCE SYSTEM AND AN INTERFERENCE METHOD - An interference system, comprising:
| 02-18-2016 |
20160087796 | STRING PROCESSOR - According to one embodiment is a string processor configured to output a biased output string having a first output value and a second output value. The string processor is given an unbiased input string of at least two input values. The string processor has a processing unit and a memory device, the memory device stores a code-word set. The code-word set has a plurality of code-words, each code-word having at least one input value, and each output value has at least one corresponding code-word. The processing unit is configured to: compare a comparison string to the code-word set, wherein the comparison string includes an input from the input string; and assign an output value to the output string when the comparison string matches a code-word. The assigned output value is that to which the matched code-word corresponds. An output probability of an output value is defined by the number and length of the code-words corresponding to that output value; and the output probability of the first output value is larger than the output probability of the second output value. | 03-24-2016 |