6 results about "Coherence time" patented technology

A terminal is disclosed including a processor that measures for beam management: a Doppler spread or a coherence time associated with a beam and one or more reporting quantities. The terminal also includes a transceiver that reports the Doppler spread or the coherence time. In other aspects, a method for a terminal and a base station are also disclosed.

Disclosed herein is a method of quantum communication comprising transmitting photons from at least two different transmitters 202, 204, and receiving the transmitted photons at a receiver 208. Receiving the photons involves interfering the received photons 210 in interference events, registering detections of photons from the interference events, using at least two different detectors 212, 214, and analysing the interference events. Analysing the interference includes distinguishing between a single-photon interference event and a two-photon interference event, the latter describing two single-photon interference events occurring either simultaneously or within a coherence time of the photons. The transmitting step preferably involves encoding a first portion of the transmitted photons with quantum states chosen from a first basis and encoding a second portion of transmitted photons with quantum states chosen from a second basis. The analysing interference step allows the basis to be identified, because single-photon interference events may be associated with the first basis, and two-photon interference events with the second basis.

The invention provides an incoherent light long-distance three-dimensional imaging device using multi-beam synthesis, and relates to the technical field of incoherent light correlated imaging. The three-dimensional imaging device adopts multi-beam emission and optical synthetic aperture receiving, the number of emission beams can be increased according to application scenes, the emission power is improved, and the three-dimensional imaging device is suitable for long-distance imaging; the increase of the receiving aperture baseline can further improve the imaging resolution; in addition, long-distance amplitude random and phase random incoherent light synthesis can be realized by utilizing multi-channel modulation and atmosphere random modulation; according to the mode of combining active and passive amplitude and phase random modulation, a high-collimation, high-intensity and narrow-band thermal light source is synthesized, the disadvantage of short coherence time caused by inherent periodicity of active modulation and too low atmospheric modulation speed is made up, and anti-turbulence high-resolution three-dimensional imaging of a long-distance target can be achieved through second-order coherence of the light source.

In some embodiments, an optical communication system may include a light source, a modulator, and an optical receiver. The light source may be configured to generate a beam comprising a series of light pulses. The optical receiver may have a detection window duration of 1 nanosecond or less. As the first pulse travels through a variable refractive medium, photons in the first pulse may be refracted, thus traveling along different ray paths to reach the optical receiver according to a time distribution curve. The full width at half maximum (FWHM) value of the time distribution curve may be greater than the coherence time value of the first pulse, and the detection window of the optical receiver may be greater than the FWHM value of the time distribution curve.

In some embodiments, an optical communication system may include an optical source, a modulator, and a photoreceiver. The optical source may be configured to generate a beam comprising a series of light pulses each having a duration of less than 100 picoseconds. The photoreceiver may have a detection window duration of less than 1 nanosecond. When a first pulse travels through a variably refractive medium, photons in the first pulse may be refracted to travel along different ray paths to arrive at the photoreceiver according to a temporal distribution curve. A full width at half maximum (FWHM) value of the temporal distribution curve may be at least three times as large as a coherence time value of the first pulse, and the detection window of the photoreceiver may be at least six times as large as the FWHM value of the temporal distribution curve.

The invention relates to a superconducting quantum bit control reflected wave calibration method, which comprises the following steps of: integrating a reflected wave engineering mechanism in a pulse control system, pre-generating a reflected wave offset waveform which has the same frequency and the same shape as a reflected pulse and is opposite to the phase of the reflected pulse, and inhibiting a system error caused by reflection to 105 magnitude under the premise of not introducing additional hardware by combining DRAG parameter optimization; the defects that in a traditional scheme, the gate operation duration is increased, and the error rate is accumulated are overcome, finally, the overall single-bit gate fidelity is improved, the gate operation fidelity anisotropy is remarkably weakened, the single-bit gate fidelity remarkably approaches the coherence time limit of a current quantum bit, meanwhile, the modular expansion capacity is achieved, and the implementation cost is reduced. And the method can be adapted to various chip structures and large-scale parallel quantum bit systems.