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.

Provided are systems and methods for using laser interferometry to measure moving objects. Systems provided include laser interferometry systems comprising: a laser emitter configured to emit a laser beam; a beam splitter configured to split the emitted laser beam into a first split beam directed towards a deflector and a second split beam, wherein the first split beam comprises a first beam diameter and a second beam diameter, the first beam diameter being greater than the second beam diameter, and the second split beam comprises a third beam diameter and a fourth beam diameter, the third split beam diameter being greater than the fourth beam diameter; and a deflector configured to deflect the first split beam to intersect with the first split beam, wherein the first beam diameter and the third beam diameter are parallel.

Provided are systems and methods for using laser interferometry to measure moving objects. Systems provided include laser interferometry systems comprising: a laser emitter configured to emit a laser beam; a beam splitter configured to split the emitted laser beam into a first split beam directed towards a deflector and a second split beam, wherein the first split beam comprises a first beam diameter and a second beam diameter, the first beam diameter being greater than the second beam diameter, and the second split beam comprises a third beam diameter and a fourth beam diameter, the third split beam diameter being greater than the fourth beam diameter; and a deflector configured to deflect the first split beam to intersect with the first split beam, wherein the first beam diameter and the third beam diameter are parallel.

The invention refers to an optical device for heterodyne interferometry, comprising a chip, a beam splitter, a first waveguide arranged on the chip, light propagating in the first waveguide being guided to the beam splitter, a second waveguide arranged on the chip, light propagating in the second waveguide being guided to and/or from the beam splitter, wherein the beam splitter, the first waveguide, and the second waveguide form part of a Michelson interferometer, wherein the first waveguide and the second waveguide at least partially form two arms of the Michelson interferometer, and wherein two further arms of the Michelson interferometer are at least partially arranged outside the chip.

A homodyne encoder system has adaptive matching of path lengths. Primary apertures receive light from a target. An optical spreader spreads apart the light passing through the primary apertures by at least a factor of two times a baseline separation of the primary apertures. The optical spreader includes a plurality of actuators for modifying the path lengths within the homodyne encoder system through the primary apertures to a detector. A focusing optic focuses the light from the optical spreader at the detector. The detector detects an image of the target with the light from the focusing optic.

An OCT imaging system may include an OCT light source operable to emit an OCT light beam, and a beam splitter operable to split the OCT light beam into a sample beam, transferred to a sample arm waveguide, and a reference beam, transferred to a reference arm waveguide. The sample arm waveguide and the reference arm waveguide may be coupled together within a cladding, wherein the cladding improves a calibration of a generated OCT image by fixing axial movement of the sample arm and reference arm waveguides relative to one another. By routing long reference and sample arm waveguide fibers together in the OCT system using a sheath/cladding, OCT image offset due to asymmetrical fiber stretching can be minimized or eliminated.

A background subtraction method and tilt stage device for eliminating contaminated or spurious interference patterns by reducing retrace errors. An optical reference surface secured in a pivoting mount coupled to a tilt actuator is configured to angularly displace the pivoting mount and optical reference surface. A microcontroller coupled to the tilt actuator controls the tilt displacement of the tilt actuator providing a plurality of wavefront measurements of the reference surface at a plurality of angles to provide a system and method for background measurement.

A background subtraction method and tilt stage device for eliminating contaminated or spurious interference patterns by reducing retrace errors. An optical reference surface secured in a pivoting mount coupled to a tilt actuator is configured to angularly displace the pivoting mount and optical reference surface. A microcontroller coupled to the tilt actuator controls the tilt displacement of the tilt actuator providing a plurality of wavefront measurements of the reference surface at a plurality of angles to provide a system and method for background measurement.

An analysis apparatus includes an acquisition part that acquires a plurality of interference images of the object to be measured from the interference measurement apparatus, a calculation part that calculates a sine wave component and a cosine wave component of an interference signal for each pixel in the plurality of interference images, respectively, an error detection part that detects an error between a first Lissajous figure constructed on the basis of the sine wave component and the cosine wave component for each pixel and an ideal second Lissajous figure, a correction part that corrects the sine wave component and the cosine wave component for each pixel on the basis of the error, and a geometry calculation part that calculates surface geometry of the object to be measured on the basis of the corrected sine wave component and cosine wave component.

A displacement detection device is capable of stably and accurately detecting an amount of displacement. A polarization maintaining fiber has a length not to be equal to a length obtained by dividing, a product of an integral multiple of twice a length of a resonator times a refractive index of the resonator and a beat length obtained from a difference between propagation constants of two polarization modes, by a wavelength of the light source, is selected from a range including a length equal to the above length. The polarization maintaining fiber includes multiple polarization maintaining fibers fitted to each other by removable connectors.