Provided is an optical measurement device configured so that a high-accuracy three-dimensional image can be obtained. An emission angle of a ray of light is changed in such a manner that the rotation frequencies of two motors configured to rotatably drive a first optical path changing unit and a second optical path changing unit is controlled. The ray of light is emitted to a front three-dimensional region, and reflected light is obtained. Then, calculation is made by a computer, and in this manner, three-dimensional data on a measurement target object is obtained. The amount (vibration amount) of axial backlash or play of a rotary mechanism, such as a motor shaft, along which the ray of light is emitted is measured in real time, and such a backlash or play amount is subtracted from a three-dimensional image obtained by the computer. Consequently, a high-accuracy three-dimensional image is obtained.

Disclosed is a technology for stabilizing a phase using a modulator bias controller and a laser that emits a beam with a frequency fixed.

An optical interrogation system, e.g., an OFDR-based system, measures local changes of index of refraction of a sensing light guide subjected to a time-varying disturbance. Interferometric measurement signals detected for a length of the sensing light guide are transformed into the spectral domain. A time varying signal is determined from the transformed interferometric measurement data set. A compensating signal is determined from the time varying signal which is used to compensate the interferometric measurement data set for the time-varying disturbance. The compensation technique may be applied along the length of the light guide.

A system for monitoring states of cells in a bioreactor, the system including: an optical coherence tomography system including: a reference arm coupled to a mirror; a sample arm coupled to an optical probe configured to emit an imaging beam into a bioreactor; a light source; and a spectrometer configured to detect recombined light reflected along the reference arm and the sample arm; and a controller comprising a processor and memory, the controller being configured to receive spectrometer data from the optical coherence tomography system and to compute statistics of objects detected by the optical coherence tomography system.

This disclosure relates to the field of Optical Coherence Tomography (OCT). This disclosure particularly relates to an OCT system with improved motion contrast. This disclosure particularly relates to motion contrast methods for such OCT systems. The OCT system of this disclosure may have a configuration that scans a physical object, which has a surface and a depth, with a beam of light that has a beam width and a direction; acquires OCT signals from the scan; forms at least one A-scan using the acquired OCT signals; forms at least one B-scan cluster set using the acquired OCT signals that includes at least two B-scan clusters that each include at least two B-scans. The B-scans within each B-scan cluster set are parallel to one another and parallel to the direction of the beam of light. The OCT system may have a configuration that calculates OCT motion contrast using the at least one B-scan cluster set. This OCT system may form and display an image of the physical object.

Higher-precision measurement is achieved by an optical inner surface measuring device configured to cause a probe to enter into the inner peripheral surface or deep hole of a target object, capture and observe reflection light from the inner surface in a three-dimensional manner, and measure the accuracy of the target object. In a structure including an optical fiber built into a tube, a light path conversion unit arranged at a leading end side of the optical fiber, and a motor configured to rotationally drive the light path conversion unit, a unit for measuring the amount of runout of a rotation shaft unit of the motor is provided. Shape data on the inner peripheral surface of a target object is obtained by calculating at a computer reflection light from the target object, and is modified by displacement amount data from a displacement measurement unit to realize high-precision measurement with no measurement error resulting from runout and rotational vibration of the rotation shaft of the motor.

A metrology system including a heterodyne light source is provided. The heterodyne light source includes a first light source, an acousto-optic modulator and a source optical arrangement. The acousto-optic modulator receives at least one wavelength laser beam from the first light source and generates at least one corresponding frequency shifted laser beam (e.g., with orthogonal polarization). The source optical arrangement includes a receiving optical element portion and a birefringent optical element portion. The receiving optical element portion receives the wavelength laser beam(s) and the corresponding frequency shifted laser beam(s) and directs the beams along an optical path toward the birefringent optical element portion. The birefringent optical element portion combines the beams to output a combined beam (e.g., which may be utilized as part of a measurement process to determine at least one measurement distance to at least one surface point on a workpiece, etc.).

Method for calibrating and correcting the scanning distortion of any optical coherence tomography system by using reference patterns and obtaining mathematical relationships between the positions of the reference points in a reference pattern and the local coordinates of said reference points, said coordinates are obtained by means of said optical coherence tomography system.

This disclosure relates to the field of Optical Coherence Tomography (OCT). This disclosure particularly relates to an OCT system with improved motion contrast. This disclosure particularly relates to motion contrast methods for such OCT systems. The OCT system of this disclosure may have a configuration that scans a physical object, which has a surface and a depth, with a beam of light that has a beam width and a direction; acquires OCT signals from the scan; forms at least one A-scan using the acquired OCT signals; forms at least one B-scan cluster set using the acquired OCT signals that includes at least two B-scan clusters that each include at least two B-scans. The B-scans within each B-scan cluster set are parallel to one another and parallel to the direction of the beam of light. The OCT system may have a configuration that calculates OCT motion contrast using the at least one B-scan cluster set. This OCT system may form and display an image of the physical object.

A method for measuring a surface shape of an optical element, wherein the optical element has a main body with a substrate and a reflective surface, and wherein at least one cooling channel for receiving a coolant is formed in the substrate, comprising: a) recording a cooling channel pressure, b) recording a measurement environment pressure, c) determining a pressure difference based on the cooling channel pressure and the measurement environment pressure, d) comparing the pressure difference with a predetermined target pressure difference, e) monitoring for a deviation between the pressure difference and the target pressure difference, wherein, if a deviation greater than a predetermined limit value is detected, the cooling channel pressure is adapted in such a way that the deviation becomes less than or equal to the predetermined limit value, and f) measuring the surface shape if the deviation is less than or equal to the predetermined limit value.