An optical interferometer includes a branching-combining unit, a first optical system, a second optical system, and a drive unit. The branching-combining unit includes a branching surface, an incident surface, a first output surface, a combining surface, and a second output surface on an interface of a transparent member, the branching surface partially reflects incident light and outputs as first branched light, and transmits the rest of the incident light into the interior as second branched light, the combining surface partially combines the first branched light and the second branched light to be output to the outside as first combined light, and combines the rest of the first branched light and the second branched light to be propagated into the interior as second combined light, and the second output surface partially outputs the second combined light to the outside.

A system and method for metrology and profilometry using a light field generator are disclosed. For this purpose, a system such as an optical analysis system scans a sample using light, and detects light reflected off a sample in various ways. The system operates different operational modes including a backscatter intensity, a triangulation, and an interferometric mode. For this purpose, the optical analysis system includes one or more optical angle modulation systems, such as surface acoustic wave (SAW) modulators, that emit light, a sample holder, and a scanning system that scans the one or more SAW modulators relative to the sample holder. The system performs tomographic reconstructions of information generated by the scans to create 3D maps/volume datasets of the sample.

A phase-resolved heterodyne shearing interferometer has been developed for high-rate, whole field observations of transient surface motion. The sensor utilizes polarization multiplexing and multiple carrier frequencies to separate each segment of a shearing Mach-Zehnder interferometer. Post-processing routines have been developed to recombine the segments by extracting the scattered object phase from Doppler shifted intermediate carrier frequencies, providing quantitative relative phase changes and information to create variable shear, phase resolved shearographic fringe patterns without temporal or spatial phase shifting.

A position measurement system configured to measure a position of an object. The system includes an optical system to obtain a first measurement wave and a second measurement wave from a radiation source, and to allow the first and second measurement wave to at least partially interfere with each other after interaction of at least one of the first and second measurement wave with the object to form a first detection beam. The system further includes a first detector to receive the first detection beam. The system also has a processing unit configured to receive an output from the first detector and to determine a signal representative for the position of the object from the output, wherein the optical system includes a phase modulator configured to modulate a phase difference between the first measurement wave and the second measurement wave.

A method for constructing a three-dimensional image of a sample includes producing electromagnetic radiation and directing the produced electromagnetic radiation such that it is incident on the sample at an oblique angle. The incident electromagnetic radiation is scanned in discrete increments to a plurality of discrete locations along a first direction, and at each discrete location, scanned along a second direction orthogonal to the first direction. The sample reflects a first portion of the incident electromagnetic radiation and absorbs a second portion of the incident electromagnetic radiation, and emits electromagnetic radiation responsive to the absorption. A plurality of cross-sectional images is produced from the reflected electromagnetic radiation and the emitted electromagnetic radiation, and each cross-sectional image is modified to compensate for the oblique angle. The modified cross-sectional images are then combined to create a three-dimensional image of the sample.

A position measurement system configured to measure a position of an object. The system includes an optical system to obtain a first measurement wave and a second measurement wave from a radiation source, and to allow the first and second measurement wave to at least partially interfere with each other after interaction of at least one of the first and second measurement wave with the object to form a first detection beam. The system further includes a first detector to receive the first detection beam. The system also has a processing unit configured to receive an output from the first detector and to determine a signal representative for the position of the object from the output, wherein the optical system includes a phase modulator configured to modulate a phase difference between the first measurement wave and the second measurement wave.

A measurement system is presented for use in metrology measurements on patterned samples. The system comprises: at least one light source device configured to generate broadband light, at least one detection device configured to provide spectral information of detected light, and an optical system. The optical system comprises at least an oblique channel system for directing incident light generated by the light source(s) along an oblique illumination channel onto a measurement plane, on which a sample is to be located, and directing broadband light specularly reflected from the sample along a collection channel to the detection device(s). The optical system further comprises an interferometric unit comprising a beam splitting/combining device and a reference reflector device. The beam splitting/combining device is accommodated in the illumination and collection channels and divides light propagating in the illumination channel into sample and reference light beams propagating in sample and reference paths, and combines reflected

The present disclosure relates to a three-dimensional shape measurement apparatus for obtaining height information of a measurement target object using a prism. The three-dimensional shape measurement apparatus includes an illumination unit irradiating light on the measurement target object, a prism unit receiving reflective light reflected from the measurement target object and directing the reflective light to an image formation lens, an imaging unit receiving the reflective light from the prism unit and capturing an image of the reflective light, and a height measurement unit measuring a height of the measurement target object based on the image captured by the imaging unit.

A phase-resolved heterodyne shearing interferometer has been developed for high-rate, whole field observations of transient surface motion. The sensor utilizes polarization multiplexing and multiple carrier frequencies to separate each segment of a shearing Mach-Zehnder interferometer. Post-processing routines have been developed to recombine the segments by extracting the scattered object phase from Doppler shifted intermediate carrier frequencies, providing quantitative relative phase changes and information to create variable shear, phase resolved shearographic fringe patterns without temporal or spatial phase shifting.

An incoming laser source beam is projected to a glass disc having a frosted upper surface. A refracted beam and a reflected beam are produced from the laser source beam. The refracted beam is reflected back to and through the glass disc to combine with the reflected beam to form an interference pattern on the target.