The invention relates to a method for monitoring time-dependent properties of light during scanning swept-source optical coherence tomography, having the steps: a. generating laser light having wavelengths that change on a time-dependent basis and a predetermined sweep duration; b. splitting the laser light into sample light, reference light, and monitor light; c. routing the reference light into a reference arm of an OCT interferometer; d. routing the monitor light into a monitor device, which generates at least one optical monitor signal representing at least one time-dependent property of the monitor light; e. generating at least one electric monitor signal from the at least one optical monitor signal with a light detector; f. illuminating in a point-shaped manner a sample with sample light, wherein the illumination point is guided on the surface of the sample along a predetermined trajectory; g. superimposing the light scattered by the sample with the reference light emerging from the reference arm on a light detector to generate an electric OCT signal;
characterized in that h. the at least one electric monitor signal and the electric OCT signal are AD-converted in alternating sequence, in each case equidistantly in time, by means of which a single digital data stream comprising time segments each having only one of the AD-converted signals is formed.

Integrated photonic chips and related systems and methods suitable for space-division multiplexing optical coherence tomography scanning are disclosed. In one embodiment, the photonic chip comprises a substrate, an optical input port which receives an incident sampling beam from an external light source, a plurality of optical output ports configured to transmit a plurality of sampling beams from the chip to a sample to capture scanned images of the sample, and a plurality of interconnected and branched waveguide channels formed in the substrate. Waveguide channels in a splitter region divide the sampling beam into the plurality of sampling beams at the output ports. Terminal portions of the waveguide channels in a time delay region associated with each output port have different predetermined lengths to create an optical time delay between the sampling beams. In some embodiments, the chip further comprises an interferometer region to create interference patterns.

A laser interference device includes a measurement laser that outputs a laser beam, a beam splitter that divides the laser beam into a measurement laser beam and a frequency monitor laser beam, a reference laser that outputs a reference laser beam, a frequency detector that detects a beat frequency resulting from interference between the reference laser beam and the frequency monitor laser beam, a wavelength calculator that calculates a wavelength of the frequency monitor laser beam (a wavelength measurement value) on the basis of the beat frequency, a light detector that detects an interference light of the measurement light and the reference light of the measurement laser beam and outputs a light detection signal, and a displacement calculator that calculates a displacement of the measurement mirror by performing an arithmetic process based on the wavelength measurement value and the light detection signal.

The disclosure discloses a differential sinusoidal phase modulation laser interferometric nanometer displacement measuring apparatus and method. The beam output from the single-frequency laser is converted into a 45° linearly polarized beam after passing through the polarizer, then projected onto two sets of sinusoidal phase modulation interferometers consisting of the beam splitter, the electro-optic phase modulator, the half wave plate, three pyramid prisms, two polarization beam splitters, thereby forming measurement and reference interference signals which are received by two photodetectors. A high-frequency sinusoidal voltage signal is applied to the electro-optic phase modulator placed in the common reference arm of the two interferometers, thereby modulating the interference signal into a high-frequency AC signal. By detecting the difference between the phase change amounts of the two interference signals when the measured object moves, the measured displacement can be obtained.

The present invention provides a reflective condensing interferometer for focusing on a preset focus. The reflective condensing interferometer includes a concave mirror set, a convex mirror, a light splitting element, and a reflecting element. The concave mirror set has first and second concave surface portions which are oppositely located on two sides of a central axis passing through the preset focus and are concave on a surface facing the central axis and the preset focus. Light is preset to be incident in parallel to the central axis in use. The convex mirror is disposed between the concave mirror set and the preset focus on the central axis, and is convex away from the preset focus. The light splitting element vertically intersects with the central axis between the convex mirror and the preset focus. The reflecting element is disposed between the light splitting element and the convex mirror.

System and methods for Light Detecting and Ranging (LIDAR) are disclosed. The LIDAR system includes a light source that is configured project a beam at various wavelengths toward a wavelength dispersive element. The wavelength dispersive element is configured to receive the beam and direct at least a portion of the beam into a field of view (FOV) at an angle dependent on frequency. The system also includes a detector that is positioned to receive portions of the beam reflected from an object within the FOV and a processor that is configured to control the light source and determine a velocity of the object.

An optoelectronic system for measuring physical parameters comprising: two narrow band light sources with different peak frequencies coupled together into a combined light using a coupler. The combined light is split into a first Fabry-Pérot interferometer arranged to be exposed to both temperature and physical parameter of interest and a second Fabry-Pérot interferometer arranged to be exposed only to temperature. The system further comprises first and second optical detectors arranged to receive light reflected from the cavities of the first and second Fabry-Pérot interferometers respectively through an optical path comprising a combination of lenses and/or mirrors and a Fizeau interferometer. A processor is arranged to analyze the data received by the first optical detector and second optical detector and calculate a value for temperature and the physical parameter of interest.

Techniques for measuring optical aberrations of the eye are disclosed. An example method comprises positioning the eye in a measurement location adjacent to a measurement arm of an optical coherence tomography (OCT) interferometer apparatus, so that source light from the measurement arm passes into the anterior segment of the eye and detecting an interference pattern, the interference pattern resulting from a combination of light reflected from the eye and light reflected from a reference arm of the OCT interferometer apparatus. Based on the interference pattern, an optical delay between a reference surface in the anterior segment of the eye and a measured surface in the eye is calculated, the reference surface being the anterior surface of the cornea or the lens, wherein said calculating comprises measuring an optical phase shift between the reference surface and the measured surface, based on the detected interference pattern.

Reference and test waves are directed in a common path mode in a fiber tip diffraction interferometer. A first fiber can be used to generate the reference wave and a second fiber can be used to generate the test wave. Each fiber can include a single mode fiber tip that defines a wedge at an end without a coating on end surface or a tapered fiber tip. The fiber tip diffraction interferometer can include an aplanatic pupil imaging lens or system disposed to receive both the test wave and the reference wave and a sensor configured to receive both the test wave and the reference wave.

A digitizer and processor device for a swept-source optical coherence tomography (SS-OCT) imaging system, comprising: an input configured to receive an OCT signal; a control input configured to receive a k-clock signal; a combiner unit (130) receiving the OCT signal and the k-clock signal configured to output a composite signal; a digitizing unit (60) arranged to convert the composite signal into a digital composite signal (69); a data processing unit (70) arranged to determine a profile of optical density in a sample that generated the OCT signal based on the digital composite signal (69).