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 |