An optical coherence tomography (OCT) apparatus includes a light source unit to generate light, a coupler unit to generate coupled light using reference light and measurement light generated by splitting the light, split the coupled light into n coupled and split lights and irradiate the n coupled and split lights, wherein n is a natural number greater than or equal to 2, a detection unit to irradiate the incident n coupled and split lights to n spectroscopes respectively and sequentially scan each light separated from each of the spectroscopes by wavelength range, and an image generation unit to generate a 2-dimensional single image using a result of the scanning by the detection unit. Accordingly, it is possible to improve the OCT image acquisition rate by distributing the scan time for a plurality of split lights using a plurality of array detectors.

An optical coherence tomography (OCT) system using partial mirrors is generally described. In an example, the OCT system includes a swept light source. The system further includes an interferometer into which light from the light source is directed and a detector configured to produce an imaging sample signal based on light received from the interferometer. The system also includes a partial mirror disposed over an aperture, wherein the partial mirror is configured to transmit light within a first wavelength range and reflect light within a second wavelength range.

Multichannel optical coherence systems and methods involving optical coherence tomography (OCT) subsystems are operably and respectively connected to optical fibers of a multichannel optical probe, such that each optical fiber forms at least a distal portion of a sample beam path of a respective OCT subsystem. The optical fibers are in optical communication with distal optical elements such that external beam paths associated therewith are directed towards a common spatial region external to the housing. Image processing computer hardware is employed to process OCT signals obtained from the plurality of OCT subsystems to generate an OCT image dataset comprising a plurality of OCT A-scans and process the OCT image dataset to generate volumetric image data based on known positions and orientations of the external beam paths associated with the OCT subsystems.

An optical beam controller includes: an optical multiple-beam generator generating a plurality of wavelength-swept optical beams; and an optical frequency difference setter setting an optical frequency difference in any combination of the plurality of optical beams in such a way as to be larger than a band of a photodetector that receives an optical beam.

A method and a system for determining relative position of an element of an optical system of an assembly for processing or measuring an object along a measurement line, involve generating a measurement beam and a reference beam of low coherence optical radiation. The measurement and reference beams, alternately or in combination, have a main beam and a multiplexed additional beam. The measurement beam, led toward the element of the optical system, and back-reflected, is superimposed on the reference beam in a region of common incidence of an interferometric optical sensor arrangement. Position or frequency of a main interference fringe pattern and an additional interference fringe pattern is detected.

A digital measuring device implemented on a photonic integrated circuit, the digital measuring device including a laser source configured to provide light, a first ring resonator configured to produce a first frequency comb of light from the laser source, wherein at least a portion of the first frequency comb of light is directed at a moving object, a local oscillator configured to provide a reference beam, at least one waveguide structure configured to combine the reference beam with light reflected from the moving object to produce a measurement beam, a first multiplexer configured to split the measurement beam into a plurality of channels spaced in frequency, and a plurality of detectors configured to detect an intensity value of each channel of the plurality of channels to measure a distance between the digital measuring device and the moving object.

An interferometry apparatus comprising: a laser source operable to emit a first light beam; a beam splitter arranged to split the first light beam into an object beam and a reference beam, the object beam passing along an object beam arm and the reference beam passing along a reference beam arm; an adaptive delay line located a distance along the reference beam arm, the adaptive delay line being configured to provide, in use, one or more length-adjusted reference beams; a beam splitter arranged to recombine the object beam from the object beam arm and the length-adjusted reference beam(s) from the reference beam arm; and a photodetector operable to detect interference between the object beam and the length-adjusted reference beam(s).

A measuring device determines a distance between a processing head for a laser processing system configured to process a workpiece with a laser beam and the workpiece. The measuring device includes an optical coherence tomograph to measure a distance between the processing head and workpiece. In the optical coherence tomograph, measuring light generated by a measuring light source and reflected by the workpiece interferes with measuring light reflected in a reference arm with two or more reference stages. The stages include a first reference stage configured such that the measuring light reflected therein travels a first optical path length, and a second reference stage configured such that the measuring light reflected therein travels a second optical path length different from the first length, wherein the measuring light reflected by the workpiece interferes with reflected measuring light of the first reference stage and reflected measuring light of the second reference stage.

A composite measurement system for measuring nanometer displacement is provided. The system includes: a light source, a polarization beam splitting prism, a first phase change module, a second phase change module, a first right-angle prism, a second right-angle prism, a non-polarization beam splitting prism, a scalar interference light collection module, a vector interference light collection module and a displacement calculation module. In the present disclosure, a photodetector is configured to collect an intensity of scalar interference light of the object to be measured being moving, to obtain a periodic light intensity change curve; a CCD camera is configured to collect images of interference vortex light of the object being moving; and the displacement calculation unit is configured to calculate a displacement of the object according to integer periods of the light intensity change curve and angles of image changes of the interference vortex light.

The invention provides a wavelength tracking system comprising a wavelength tracking unit and an interferometer system. The wavelength tracking unit has reflection surfaces at stabile positions providing a first reflection path with a first path length and a second reflection path with a second path length. The first path length is substantially larger than the second path length. The interferometer system comprises: a beam splitter to split a light beam in a first measurement beam and a second measurement beam; at least one optic element to guide the first measurement beam, at least partially, along the first reflection path and the second measurement beam, at least partially, along the second reflection path; a first light sensor arranged at an end of the first reflection path to receive the first measurement beam and to provide a first sensor signal on the basis of the first measurement beam; a second light sensor arranged at an end of the second reflection path to receive the second measurement beam and to provide a second sensor signal on the basis of the second measurement beam; and a processing unit to determine a wavelength or change in wavelength on the basis of the first sensor signal and the second sensor signal.