3 results about "Homodyne detection" patented technology

This invention provides a large-scale, high-precision optical Ising computer that can significantly increase the number of spins, achieve optimal binary bifurcation for the problem to be solved using an arbitrary nonlinear function, and converge stably and quickly. [Solution] The system includes a pulse light source 1, an optical fiber loop 3 into which optical pulses from the pulse light source 1 are introduced, an erbium-doped optical fiber amplifier 4 provided within the optical fiber loop 3, a homodyne detection circuit 5 for detecting optical pulses from the optical fiber loop 3, a matrix-nonlinear calculation circuit 6 for digitally calculating an interaction function and a nonlinear function for binary branching for the optical pulses detected by the homodyne detection circuit 5, and an AM optical modulator 2 which receives the optical pulses from the pulse light source 1 and the information obtained from the digital calculations of the matrix-nonlinear calculation circuit 6, modulates the input optical pulses, and then injects them into the optical fiber loop 3.

The application discloses a microwave continuous variable quantum key distribution method and system, and relates to the technical field of quantum key distribution. The method comprises the following steps: a transmitting end performs Gaussian modulation on a coherent state of a microwave frequency, and couples the Gaussian modulation coherent state into a free space quantum channel; a receiving end performs homodyne detection on the received Gaussian modulation coherent state, and obtains a canonical component; the receiving end broadcasts a detection basis of each Gaussian modulation coherent state on an authenticated classical channel, the transmitting end retains the canonical component corresponding to the same detection basis as the receiving end, and determines N pairs of original keys according to the retained canonical component and the canonical component obtained by the receiving end; then, the N pairs of original keys are segmented into small blocks with a fixed size, and an isolation forest algorithm is used to remove abnormal small blocks in all the small blocks; and finally, both communication parties perform a post-processing protocol on the remaining small blocks through the classical channel, and obtain a secure key. The method solves the problem of short communication distance of microwave CV-QKD in the prior art.

The application belongs to the technical field of optical precision measurement, and discloses a kind of light beam displacement measurement method and device based on optical resonant cavity mode selection enhancement, device includes: laser light source system, spatial mode selection system and balanced homodyne detection system;Laser light source system is used to produce high purity HG 00 Mode as the first probe light field and HG 10 Mode as local light field;First probe light field is obtained after the reflection of second probe light field and is incident to spatial mode selection system after being measured surface reflection;Spatial mode selection system adopts optical resonant cavity to be resonant locked to carrier light field, to filter out the carrier component in second probe light field, and the purified light field is incident balanced homodyne detection system, balanced homodyne detection system is used for the homodyne detection of second probe light field and HG 10 Mode local light field, obtains displacement signal.The application can reduce the influence of carrier light field on measurement noise, improve the precision of light beam displacement measurement.