The present invention discloses a high-fidelity entangled link generation method based on quantum time-space, the method comprising: directing, by a communication provider, a laser beam to a nonlinear crystal, thereby enabling probabilistically bursting out of a photon beam, and polarizing the photon beam to be in an entangled state; at an entanglement distribution stage, enabling entangled photons to traverse through quantum trajectories, and generating a distributed entangled photon state between a first communication node and a second communication node to construct an elementary entangled link; the first communication node or the second communication node is required to select the same measurement basis for m control qubits when m copies of entangled photon pairs from entanglement source are assumed to be distributed through quantum trajectories to communication nodes with the time interval , such that 2m memory qubits of two adjacent nodes may store m exactly the same distributed entangled states.

An image data set acquired by an optical coherence tomography (OCT) system is corrected for effects due to motion of the sample. A first set of A-scans is acquired within a time short enough to avoid any significant motion of the sample. A second more extensive set of A-scans is acquired over an overlapping region on the sample. Significant sample motion may occur during acquisition of the second set. A-scans from the first set are matched with A-scans from the second set, based on similarity between the longitudinal optical scattering profiles they contain. Such matched pairs of A-scans are likely to correspond to the same region in the sample. Comparison of the OCT scanner coordinates that produced each A-scan in a matching pair, in conjunction with any shift in the longitudinal scattering profiles between the pair of A-scans, reveals the displacement of the sample between acquisition of the first and second A-scans in the pair. Estimates of the sample displacement are used to correct the transverse and longitudinal coordinates of the A-scans in the second set, to form a motion-corrected OCT data set.

At least one embodiment of the method is designed to create a two-dimensional image of a three-dimensional sample. The method comprises the following steps: provision of a wave-length-tunable light source (1) that emits primary radiation (P) with wavelengths that vary over time; sampling of location points of the sample (2) with the primary radiation (P); collection of secondary radiation (S), wherein the secondary radiation (S) is a part of the primary radiation (P) reflected by the sample (2); creation of an interferometer-based detection signal for a plurality of sample areas, each with at least one location point, using a detection unit (4), wherein the detection signal is created as a difference signal from two output signals of a beam splitter (61) that receives reference radiation (R) and/or secondary radiation (S) at two inputs, wherein the reference radiation (R) is a portion of the primary radiation (P) that is not guided to the sample (2); and determination of a brightness value for at least one of the sample areas from the associated detection signal, wherein the determination of the brightness values is not substantially based on the summation of the individual signal amplitudes of the results of a Fourier transformation.

The invention generally relates to an optical coherence tomography system that is reconfigurable between two different imaging modes and methods of use thereof.

The tomographic image capturing device of the present invention is configured to: split light from a light source (11) into measurement light and reference light; cause the measurement light and the reference light to be incident to an object (E) and a reference object (49), respectively; and capture tomographic images of the object (E) on the basis of interference light generated by superposition of the measurement light reflected from the object (E) and the reference light reflected from the reference object (49). The tomographic image capturing device has a first image capturing mode and a second image capturing mode. The first and second image capturing modes are each a mode in which the measurement light is two-dimensionally scanned to be incident to the object (E) and the tomographic images of the object (E) are captured. The two-dimensional scans in the second image capturing mode require a shorter time than that required for the two-dimensional scans in the first image capturing mode. The capturing of the tomographic images in the first image capturing mode is performed after performing adjustment of an image capturing condition necessary for capturing the tomographic images in the first image capturing mode. The adjustment is based on the tomographic images captured in the second image capturing mode.

A distance measurement device and method based on secondary mixing of inter-mode self-interference signals of optical frequency combs are provided, which relate to the field of high precision laser distance measurement technologies. A dual-comb light source emits a dual-comb laser into a detection optical module to obtain the inter-mode self-interference signals carrying the to-be-measured distance information. The detection optical module outputs the inter-mode self-interference signals into a generation, acquisition and calculation module of inter-mode self-interference secondary mixing signals to generate the inter-mode self-interference secondary mixing signals, to thereby achieve signal acquisition and obtain a distance measurement result. In this device, coarse and fine distance measurements at different scales are achieved, measurement range and accuracy can be effectively balanced by combing intermediate transition measurement scales and inter-stage transition method, strong real-time property of measurement is achieved, and the light source has low cost and the scale of the system is small.