Quantum network devices, systems, and methods are provided to enable long-distance transmission of quantum bits (qubits) for applications such as Quantum Key Distribution (QKD), entanglement distribution, and other quantum communication applications. Such systems and methods provide for separately storing first, second, third, and fourth photons, wherein the first and second photons and the third and fourth photons are respective first and second entangled photon pairs, triggering a synchronized retrieval of the stored first, second, third, and fourth photons such that the first photon is propagated to a first node, the second and third photons are propagated to a second node, and the fourth photon is propagated to a third node, and creating a new entangled pair comprising the first and fourth photons at the first and third nodes to transmit quantum information.

An optical measurement instrument includes optical coherence tomography (OCT) interferometer and a pupil retro illumination system which directs laser light onto the retina of an eye via the sample arm of the OCT interferometer. The laser light passes through an intraocular lens (IOL) implanted into the eye, and an iris camera captures an image of the eye from a portion of the light returned from the retina of the eye, the returned light also passing through the IOL. One or more fiducials of the IOL are detected from the captured image, and an angular orientation of the eye is ascertained from the one or more detected fiducials.

Quantum network devices, systems, and methods are provided to enable long-distance transmission of quantum bits (qubits) for applications such as Quantum Key Distribution (QKD), entanglement distribution, and other quantum communication applications. Such systems and methods provide for separately storing first, second, third, and fourth photons, wherein the first and second photons and the third and fourth photons are respective first and second entangled photon pairs, triggering a synchronized retrieval of the stored first, second, third, and fourth photons such that the first photon is propagated to a first node, the second and third photons are propagated to a second node, and the fourth photon is propagated to a third node, and creating a new entangled pair comprising the first and fourth photons at the first and third nodes to transmit quantum information.

Quantum network devices, systems, and methods are provided to enable long-distance transmission of quantum bits (qubits) for applications such as Quantum Key Distribution (QKD), entanglement distribution, and other quantum communication applications. Such systems and methods provide for separately storing first, second, third, and fourth photons, wherein the first and second photons and the third and fourth photons are respective first and second entangled photon pairs, triggering a synchronized retrieval of the stored first, second, third, and fourth photons such that the first photon is propagated to a first node, the second and third photons are propagated to a second node, and the fourth photon is propagated to a third node, and creating a new entangled pair comprising the first and fourth photons at the first and third nodes to transmit quantum information.

An optical measurement instrument includes optical coherence tomography (OCT) interferometer and a pupil retro illumination system which directs laser light onto the retina of an eye via the sample arm of the OCT interferometer. The laser light passes through an intraocular lens (IOL) implanted into the eye, and an iris camera captures an image of the eye from a portion of the light returned from the retina of the eye, the returned light also passing through the IOL. One or more fiducials of the IOL are detected from the captured image, and an angular orientation of the eye is ascertained from the one or more detected fiducials.

Inspecting a multilayer sample may include receiving, at a beam splitter, light and splitting the light into first and second portions; combining, at the beam splitter, the first portion of the light after being reflected from a multilayer sample and the second portion of the light after being reflected from a reflector; receiving, at a computer-controlled system for analyzing Fabry-Perot fringes, the combined light and spectrally analyzing the combined light to determine a value of a total power impinging a slit of the system for analyzing Fabry-Perot fringes; determining an optical path difference (OPD); recording an interferogram that plots the value versus the OPD for the OPD; performing the previous acts of the method one or more additional times with a different OPD; and using the interferogram for each of the different OPDs to determine the thicknesses and order of the layers of the multilayer sample.

The invention relates to a THz sensor (2) for measuring an object to be measured (6), in particular, a pipe, the THz sensor (2) comprising: a THz transceiver (10) for emitting and receiving THz radiation, a lens (14) for bundling the THz radiation emitted by the THz transceiver (10) and emitting a THz transmission beam (8) along the optical axis (A) and for receiving a THz reflection beam (15), a support device (11), on which the lens (14) and/or the THz transceiver (10) is accommodated or fastened.

Hereby, it is provided that a THz radiation-influencing compensation formation for modifying and/or reducing incident THz radiation is provided in a compensation area between the lens and the support device (11).

The invention relates to a THz sensor (2) for measuring an object to be measured (6), in particular, a pipe, the THz sensor (2) comprising: a THz transceiver (10) for emitting and receiving THz radiation, a lens (14) for bundling the THz radiation emitted by the THz transceiver (10) and emitting a THz transmission beam (8) along the optical axis (A) and for receiving a THz reflection beam (15), a support device (11), on which the lens (14) and/or the THz transceiver (10) is accommodated or fastened.

Hereby, it is provided that a THz radiation-influencing compensation formation for modifying and/or reducing incident THz radiation is provided in a compensation area between the lens and the support device (11).

An ophthalmic apparatus that includes a light source of wavelength sweeping type; a measurement optical system; a reference optical system; a light receiving element that receives interference light; a sample clock signal generator that generates a sample clock signal from the light from the light source, the sample clock signal cyclically changing at equal frequency intervals; a signal processor that samples an interference signal based on the sample clock signal, the interference signal being outputted from the light receiving element when the light receiving element receives the interference light. The ophthalmic apparatus generates period data based on the sample clock signal, the period data indicating a relationship between a period of the sample clock signal and time; and determines a processing duration of the interference signal sampled at the signal processor based on the period data.

Disclosed is a heterodyne laser interferometer based on an integrated secondary beam splitting component, which belongs to the technical field of laser application; the disclosure inputs two beams that are spatially separated and have different frequencies to the heterodyne laser interferometer based on the integrated secondary beam splitting component, wherein the integrated secondary beam splitting component includes two beam splitting surfaces that are spatially perpendicular to each other; and the two beam splitting surfaces are plated with a polarizing beam splitting film or a non-polarizing beam splitting film, and a measurement beam and a reference beam are the same in travel path length in the integrated secondary beam splitting component. The heterodyne laser interferometer of the disclosure significantly reduces periodic nonlinear errors, has the advantages of simple structure, good thermal stability, large tolerance angle and easy integration and assembly compared with other existing heterodyne laser interferometers with spatially separated optical paths, and meets the high-precision and high-resolution requirements of high-end equipment on heterodyne laser interferometry.