An asymmetric optical interferometry method, comprises the following steps: an incident light is split into two beams, and the two beams are respectively projected onto a surface of an object to be tested and a reference mirror; and then respectively pass through a first imaging lens having a larger area on the side of the object, and a second imaging lens having a smaller area on the side of the reference mirror, and overlap on a photoelectric sensor after passing through a third imaging lens to form at least one interference image (S1); the corresponding interference image is input into a computer to obtain a signal of the corresponding interference image (S2); parse the signal of the corresponding interference image to obtain a three-dimensional shape (S3) of the surface of the object. Also provide an asymmetric optical interferometry device.

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.

An optical interferometer includes a beam splitter module and an optical sensor. The beam splitter module includes a lens assembly and a splitter cube. A light incident surface of the splitter cube is substantially orthogonal to an optical axis of the lens assembly. An acute angle is between the light incident surface and a light splitting surface of the splitter cube. A sampling surface of the splitter cube is substantially parallel to the light incident surface. A light reflecting surface of the splitter cube is substantially orthogonal to the light incident surface. The light incident surface is closer to the lens assembly than the sampling surface. A reference arm is defined between a splitter position on the light splitting surface and the light reflecting surface, a sample arm is defined between the splitter position and the sampling surface, and the reference arm is longer than the sample arm.

A reflectometer or ellipsometer integrated with a processing tool includes a source module configured to generate a input beam, and a first mirror arranged to receive the input beam. The first mirror is configured to collimate the input beam and direct the input beam toward an aperture plate. The aperture plate has at least two apertures. One of the at least two apertures is arranged to define a measurement beam from a portion of the input beam, and one of the at least two apertures is arranged to define a reference beam from a portion of the input beam. An optical element is arranged within an optical path of the reference beam and outside an optical path of the measurement beam. The optical element is configured to direct the reference beam toward a third mirror. A second mirror is arranged to receive the measurement beam and focus the measurement beam through a window and onto a surface of a sample. The window forms part of a chamber of the processing tool and the sample is disposed within the chamber. At least a portion of the measurement beam is reflected from the surface of the sample as a reflected beam. The second mirror is arranged to receive the reflected beam and direct the reflected beam toward the optical element. The optical element is configured to direct the reflected beam toward the third mirror. The third mirror is arranged to receive the reference beam and the reflected beam and focus the reference beam and the reflected beam onto a collection plane.

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.

An optical fiber ring interferometer is provided, which is based on a common light path for two or more light beam pairs preferably originated from two or more light sources of a substantially different spectrum or from a single light source split spectrum and whereas each light beam of a specific pair is propagating in relative opposite directions, wherein at least one pair of light beams is utilized to detect acousto-mechanical events and to provide information regarding location and other characteristics of detected environmental disturbance.

An optical fiber ring interferometer is provided, which is based on a common light path for two or more light beam pairs preferably originated from two or more light sources of a substantially different spectrum or from a single light source split spectrum and whereas each light beam of a specific pair is propagating in relative opposite directions, wherein at least one pair of light beams is utilized to detect acousto-mechanical events and to provide information regarding location and other characteristics of detected environmental disturbance.

An optical measuring device includes a measuring head with an imaging optical unit and an evaluation unit, wherein the measuring head is connected to the evaluation unit by way of two light-guiding fibers, wherein the evaluation unit includes a light source whose light is guided through the first light-guiding fiber into the measuring head and wherein light reflected by the measurement object is guided back through the measuring head and into a second light-guiding fiber by means of a beam splitter, in such a way that outgoing and returning light are separated, wherein the fiber ends are in mutually conjugate positions, wherein the beam splitter and the fiber ends are arranged together in a connector that is separably connected to the measuring head.

An optical measuring device includes a measuring head with an imaging optical unit and an evaluation unit, wherein the measuring head is connected to the evaluation unit by way of two light-guiding fibers, wherein the evaluation unit includes a light source whose light is guided through the first light-guiding fiber into the measuring head and wherein light reflected by the measurement object is guided back through the measuring head and into a second light-guiding fiber by means of a beam splitter, in such a way that outgoing and returning light are separated, wherein the fiber ends are in mutually conjugate positions, wherein the beam splitter and the fiber ends are arranged together in a connector that is separably connected to the measuring head.

An optical device disperses a wavelength of light and includes: a dispersion element configured to transmit incident light and disperse the incident light so that an optical path is different for each wavelength and to generate first dispersed light; and a reflection unit including four reflection surfaces sequentially reflecting the first dispersed light. The first dispersed light sequentially reflected from the four reflection surfaces is incident on the dispersion element and is transmitted through the dispersion element.