A 3-D imaging system including a computer determining a plurality of coherence factors measuring an intensity contrast between a first intensity of a first region of an interference comprising constructive interference between a sample wavefront and a reference wavefront, and a second intensity of a second region of the interference comprising destructive interference between the sample wavefront and the reference wavefront, wherein the interference between a reference wavefront and a reflection from different locations on a surface of an object. From the coherence factors, the computer determines height data comprising heights of the surface with respect to an x-y plane perpendicular to the heights and as a function of the locations in the x-y plane. The height data is useful for generating a three dimensional topological image of the surface.

An apparatus for adjusting a beam path for tracking an object includes an illumination unit to generate an illumination light beam, an optical unit with a beam expander optical unit and a beam deflection unit, the beam expander optical unit being configured to divergently expand the illumination light beam and the beam deflection unit being configured to deflect the illumination light beam spatially about two different axes of rotation, a detector unit to capture a light beam reflected by the object in response to an illumination by the illumination light beam and to generate a measurement signal, an evaluation and control unit to evaluate the measurement signal and configured to determine a manipulated variable for setting an effective focal length of the beam expander optical unit and/or for setting a spatial alignment of the beam deflection unit based on the information item in respect of the illumination of the object.

A laser interferometer includes a laser light source configured to emit first laser light; an optical modulator that includes a resonator element and is configured to generate second laser light including a modulation signal; a light receiving element configured to receive the second laser light and third laser light including a sample signal; and a calculation unit configured to calculate a displacement of an object to be measured from a light reception signal based on a reference signal, in which the calculation unit includes a preprocessing unit configured to execute a preprocessing of extracting a frequency modulation component from the light reception signal and output a preprocessing signal, a demodulation processing unit configured to mix the preprocessing signal with orthogonal signals to obtain a mixed signal and then execute a demodulation processing of extracting the sample signal from the mixed signal, and an orthogonal signal generation unit configured to generate the orthogonal signals based on a phase of the reference signal and an amplitude of the preprocessing signal.

A frequency shift light modulator includes a resonator and a diffraction grating including a plurality of grooves arranged in parallel in a displacement direction of the resonator, and the diffraction grating is provided on the resonator. By providing the diffraction grating on the resonator, it is easy to realize miniaturization and increase in accuracy of the frequency shift light modulator. Further, it is easy to realize application to a high frequency region in a MHz band, that is, high frequency modulation. It is possible to efficiently obtain an effect based on a combination of the resonator and the diffraction grating.

A laser interferometer includes: a laser light source configured to emit laser light; a light shielding element having an opening through which the laser light passes; an optical modulator configured to modulate the laser light into reference light having a different frequency; and a light receiving element configured to receive object light generated by reflecting the laser light by an object to be measured and the reference light and output a light receiving signal. 0.10≤φ.sub.pin≤10.0, in which φ.sub.pin [mm] is a diameter of the opening.

A frequency shift light modulator includes a resonator and a diffraction grating including a plurality of grooves arranged in parallel in a displacement direction of the resonator, and the diffraction grating is provided on the resonator. By providing the diffraction grating on the resonator, it is easy to realize miniaturization and increase in accuracy of the frequency shift light modulator. Further, it is easy to realize application to a high frequency region in a MHz band, that is, high frequency modulation. It is possible to efficiently obtain an effect based on a combination of the resonator and the diffraction grating.

A distance measurement device includes: a signal acquisition unit to acquire an electric signal based on interference light from an optical sensor device that splits sweep light having a periodically changing frequency into reference light and irradiation light to be emitted toward an object to be measured, irradiates the object with the irradiation light, generates interference light by causing the reference light to interfere with reflected light that is the irradiation light reflected by the object, and generates the electric signal based on the generated interference light; a frequency calculation unit to calculate, on the basis of the electric signal based on the interference light, a peak frequency of the electric signal using LASSO regression; a distance measurement unit to measure, on the basis of the peak frequency, a distance from a predetermined reference point to the object; and a distance output unit to output distance information indicating the distance.

A system for compensating for phase noise, with particular application in lidar, includes a compensation interferometer that receives a signal from a source, and splits it into a first and second path, with a path length difference Δτ between them. Typically the path length is significantly less than that of the return distance to a target. The output of the compensation interferometer, which consists of phase noise generated in time Δτ is vectorially summed during a time similar to a signal flight time to a target, and the result used to reduce phase noise present on measurements of a target. It further includes means for selecting Δτ such that competing noise elements are reduced or optimised.

A fast measurement method for micro-nano deep groove structure based on white light interference, including: establishing a white light interference system, using the white light interference system to measure the structure of the groove, the CCD camera collects and obtains multiple groups of groove interferograms and the serial number corresponding to each groove interferogram in each group; processing each group of groove interferograms of the groove sample to obtain the maximum contrast of each group of groove interferograms and the 3D reconstruction diagram of the local structure; extracting the interface reconstruction diagram in the 3D reconstruction diagram of the local structure according to each group of the groove interferograms; after splicing the interface reconstruction diagrams corresponding to all groups of groove interferograms, obtaining a 3D structural reconstruction diagram of the groove sample, and measuring the depth and width of the groove sample according to the 3D structural reconstruction diagram.

An ophthalmic intraoperative imaging system may include a handheld light probe including a first optical fiber and a second optical fiber. The system may include an illumination light source configured to transmit an illumination beam for intraocular illumination via the first optical fiber of the light probe. The system may include an optical coherence tomography (OCT) light source configured to transmit an OCT beam towards an intraocular region of interest (ROI) via the second optical fiber of the light probe. The system may include an OCT detector configured to detect light reflected by the intraocular ROI. The system may include a processor configured to control the illumination light source and the OCT light source, obtain an OCT signal, obtain a B-mode OCT image of the intraocular ROI by freehand sweeping of the handheld light probe across the intraocular ROI, and control a display to display the B-mode OCT image.