312 results about "Photon source" patented technology

A system and method for quantum key delivery in a single-photon, free-space cryptography scheme including a transmitter and a receiver. The transmitter includes two pairs of photon sources, each of which represents a specific photon polarization direction. The first pair of photon sources represents a first polarization basis while the remaining pair of photon sources represents a second polarization basis. The first and second polarization basis are rotated with respect to each other so as to produce non-orthogonal polarization eigenstates. A transmitter polarizing beamsplitter corresponding to each of the pairs of the photon sources is provided whereby the polarizations of each of the photon sources of each pair of photon sources are recombined. A transmitter non-polarizing beamsplitter is provided whereby the recombined polarizations are combined for output to the receiver. The receiver includes a set of optics inversely disposed with respect to the optics of the transmitter and two pairs of photon detectors.

A system and method for quantum key distribution uses a regulated single-photon source to sequentially generate a first photon and a second photon separated by a time interval Δt. The two photons are directed through a beam splitter that directs each photon to one of two transmission lines, which lead to two respective receivers. When one of the photons arrives at a receiver, it passes through an interferometer. One arm of the interferometer has a path length longer than the other arm by an amount equivalent to a photon time delay of Δt. The photon is then detected in one of three time slots by one of two single-photon detectors associated with each of the two interferometer outputs. Due to quantum-mechanical entanglement in phase and time between the two photons, the receivers can determine a secret quantum key bit value from their measurements of the time slots in which the photons arrived, or of the detectors where the photons arrived.

A laser driven light source comprises laser and focusing optics. These produce a beam of radiation focused on a plasma forming zone within a container containing a gas (e.g., Xe). Collection optics collects photons emitted by a plasma maintained by the laser radiation to form a beam of output radiation. Plasma has an elongate form (L>d) and collecting optics is configured to collect photons emerging in the longitudinal direction from the plasma. The brightness of the plasma is increased compared with sources which collect radiation emerging transversely from the plasma. A metrology apparatus using the light source can achieve greater accuracy and/or throughput as a result of the increased brightness. Back reflectors may be provided. Microwave radiation may be used instead of laser radiation to form the plasma.

A magnetic resonance imaging (MRI) imaging system, including: an MRI device adapted to image at least a portion of an animal; a photon source; an imaging photon detector that detects photons emitted by the photon source; and an image processor that superimposes the MRI image and the photon detector image. The system also includes one or more polarizers located between the animal and the photon detector.

A quantum cryptographic key distribution (QKD) transmitter includes an integrated photonic circuit configured to distribute encryption key material using quantum cryptographic mechanisms. The integrated photonic circuit further includes a first photon source, an interferometer coupled to the first photon source and a phase modulator coupled to the interferometer and configured to modulate a phase of photons emitted by the first photon source.

Non-destructive testing apparatus may comprise a photon source and a source material that emits positrons in response to bombardment of the source material with photons. The source material is positionable adjacent the photon source and a specimen so that when the source material is positioned adjacent the photon source it is exposed to photons produced thereby. When the source material is positioned adjacent the specimen, the specimen is exposed to at least some of the positrons emitted by the source material. A detector system positioned adjacent the specimen detects annihilation gamma rays emitted by the specimen. Another embodiment comprises a neutron source and a source material that emits positrons in response to neutron bombardment.

This invenion discloses a distribution system for quantum ciphered keys testing polarization of phase coding, in which, a transmitting party is connected with a receiving party by a quantum channel and either of which includes a same polarized beam splitting and merging device with four ports, the reflection port of which is connected with a phase modulator and a 90deg. rotation Faraday mirror orderly to form a long circuit and a transmission port of which is conneted with the 90deg. rotation Faraday mirror to form a short circuit, the incident port of the beam splitting and merging device is connected with a single photon source and the exit port is connected to a common port of a lambda/2 wave plate and a three-port polarized splitting/merging device, the reflection and the transmission ports of which are connected with a single-photon detector.

A quantum cascade source, such as a QC laser, is provided comprising a plurality of repeat units each including an active region and an injector region. The active region includes at least two quantum wells that, in response to an applied electrical bias, provide a first, second, and third electron energy level, each resulting from a respective quantum well excited state. The first and second energy levels are configured so that an electron transition from the first energy level to the second energy level emits a photon of a selected wavelength. The second and third energy levels are configured so that an electron transition from the second energy level to the third energy level comprises a nonradiative transition to empty the second energy level sufficiently quickly to promote a population inversion between the first and second energy levels.

The invention discloses a single-photon source, which realizes the electrical injection with the photonic crystal micro cavity and the wafer bonding technology. The single-photon source comprises a bottom electrode, an n-shaped substrate, a lower DBR, a photonic crystal micro cavity, an upper DBR, a p-shaped contact layer and a top electrode, which are arranged in sequence from bottom to top; wherein, the photonic crystal micro cavity of the single-photon source is provided with semiconductor quantum dots; the air hole type photonic crystal defect cavity with a two-dimensional photonic lattice is adopted; the single-photon source realizes the combination of the photonic crystal micro cavity and the upper DBR by adopting the wafer bonding technology; and the electrodes of the single-photon source are evaporated on the upper surface of the p-shaped contact layer and the lower surface of the n-shaped substrate of the upper DBR. The single-photon source not only realizes the electrical injection, but also improves the emission efficiency of the single-photon source.

The invention provides a system apparatus and methods for fragmenting various molecules. In particular, the invention may be employed for fragmenting biomolecules like peptides to determine sequence information. The invention provides a mass spectrometry system for photo-activated collision induced dissociation. The mass spectrometry system or device includes an ion source for producing ions, a photon source adjacent to the ion source for photo-activating ions produced by the ion source, an electrical element adjacent to the photon source for creating an electric field for accelerating ions produced by the ion source and photo-activated by the photon source; wherein ions are produced by the ion source, photo-activated by the photon source and accelerated into a surface to cause dissociation of the activated ions; and a detector downstream from the ion source for detecting the collision induced and dissociated ions.

Methods for molecule and/or peptide fragmentation are also disclosed.

A compact, tunable, high-efficiency entangled photon source system that utilizes first and second periodically poled waveguides rather than bulk media in order to decrease the required pump power by up to several orders of magnitude. The first and second waveguides are arranged in respective arms of an interferometer. Each waveguide has partially reflecting ends, and are each placed on the Z-face of respective periodically poled KTP or LiNBO3 crystals to form respective first and second Fabry-Perot cavities. All waves (pump, idler, and signal) are co-polarized along the z-axis of the crystals. One of the waveguides is followed by a polarization rotator (shown as a half-wave-plate in the Figures) rotating the idler and signal wave polarization by 90 degrees. The outputs from two interferometer arms are combined by a polarization beam combiner and then split by a wavelength multiplexer into two spatially separated time-bin and polarization entangled beams. Another light source, a single frequency stabilized C-band laser (stabilization laser) is used to synchronize cavities spectral modes and phase-lock their outputs.

A photon source for emitting entangled photons, the source comprising:

• • at least one quantum dot having a degenerate exciton level; and
  • exciton creation means to create a biexciton or higher order exciton within the at least one quantum dot.

A method of investigating the location and size of a light-emitting source in a subject is disclosed. In practicing the method, one first obtains a light intensity profile by measuring, from a first perspective with a photodetector device, photons which (i) originate from the light-emitting source, (ii) travel through turbid biological tissue of the subject, and (iii) are emitted from a first surface region of interest of the subject. The light-intensity profile is matched against with a parameter-based biophotonic function, to estimate function parameters such as depth and size. The parameters so determined are refined using data other than the first measured light intensity profile, to obtain an approximate depth and size of the source in the subject. Also disclosed is an apparatus for carrying out the method.

An image projection display system comprises a variable optical property element (1). The element (1) is under direction of a control system (2) and is positioned within an optical system (5), comprising optical elements (5(a, b, c, d, e, f, g)). A source image electronic device (4) receives inputs from a video generation system (7) and is illuminated with light from a photon source (11) filtered by a wavelength-selecting colour wheel (5(b)), under direction of an illumination control system (6). The element 1 comprises a thin Al-coated membrane (150) etched from S^a3N4 (151) mounted via spacers (153) over a substrate (152) having actuator pads (154). Circuits (155) supply various control voltages Electrostatic attraction causes the membrane (150) to deform towards the actuator pads (154) when voltages V1, V2, . . . VN are applied to the actuation channels. The control system (2) receives inputs from the illumination control system (6), the video generation system (J), the source image formation device (4), the mechanical positioning and sensing system (12), and vice-versa.