The interferometer 10 according to this disclosure includes: a first optical component 12 that splits each of the P polarization component and the S polarization component of the light to be measured into the first optical path R1 and the second optical path R2 and combines the light to be measured; a second optical component 13 placed in the first optical path; a third optical component 14 that splits the light to be measured into the P polarization component and the S polarization component; and a P polarization detector 11a and an S polarization detector 11b that respectively detect the P polarization component and the S polarization component split by the third optical component, wherein the second optical component has an optical surface that changes the propagation direction of the light to be measured and gives a phase difference between the P polarization component and the S polarization component.

The invention discloses a method for measuring a complex degree of coherence of a random optical field by using a mutual intensity-intensity correlation, including the steps of: building a test optical path; rotating a quarter-wave plate to enable the fast axis of the quarter-wave plate to be consistent with a polarization direction of reference light, to obtain light intensity distribution information of a first combined light; rotating the quarter-wave plate to enable the slow axis of the quarter-wave plate to be consistent with the polarization direction of the reference light, to obtain light intensity distribution information of a second combined light; blocking the reference light to obtain light intensity distribution information of to-be-tested light; blocking the to-be-tested light to obtain light intensity distribution information of the reference light; and calculating the amplitude and phase of a complex degree of coherence of the to-be-tested light.

A polarization holographic microscope system is disclosed. The polarization holographic microscope system can acquire a birefringence image and a three-dimensional phase image with high sensitivity by aperture synthesis of sample beams at various angles, and a sample image acquisition method using the microscope system.

A digital measuring device implemented on a photonic integrated circuit, the digital measuring device including a laser source configured to provide light, a first ring resonator configured to produce a first frequency comb of light from the laser source, wherein at least a portion of the first frequency comb of light is directed at a moving object, a local oscillator configured to provide a reference beam, at least one waveguide structure configured to combine the reference beam with light reflected from the moving object to produce a measurement beam, a first multiplexer configured to split the measurement beam into a plurality of channels spaced in frequency, and a plurality of detectors configured to detect an intensity value of each channel of the plurality of channels to measure a distance between the digital measuring device and the moving object.

A metrology system is disclosed, in accordance with one or more embodiments of the present disclosure. The metrology system includes a stage configured to secure a sample, one or more diffraction-based overlay (DBO) metrology targets disposed on the sample. The metrology system includes a light source and one or more sensors. The metrology system includes a set of optics configured to direct illumination light from the light source to the one or more DBO metrology targets of the sample, the set of optics including a half-wave plate, the half-wave plate selectively insertable into an optical path such that the half-wave plate selectively passes both illumination light from an illumination channel and collection light from a collection channel, the half-wave plate being configured to selectively align an orientation of linearly polarized illumination light from the light source to an orientation of a grating of the one or more DBO metrology targets.

A metrology system is disclosed, in accordance with one or more embodiments of the present disclosure. The metrology system includes a stage configured to secure a sample, one or more diffraction-based overlay (DBO) metrology targets disposed on the sample. The metrology system includes a light source and one or more sensors. The metrology system includes a set of optics configured to direct illumination light from the light source to the one or more DBO metrology targets of the sample, the set of optics including a half-wave plate, the half-wave plate selectively insertable into an optical path such that the half-wave plate selectively passes both illumination light from an illumination channel and collection light from a collection channel, the half-wave plate being configured to selectively align an orientation of linearly polarized illumination light from the light source to an orientation of a grating of the one or more DBO metrology targets.

A pixelated color mask is combined with a pixelated polarization mask in dynamic interferometry. The color mask includes a wavelength-selective bandpass filter placed in front of each camera pixel such that each set of contiguous four camera pixels is covered by two green bandpass filters, a red bandpass filter, and a blue bandpass filter. The pixelated phase mask is coupled to the color filters such that one polarization filter covers one set of color filters. At least three polarization filters are used to calculate phase. In addition, the color signals can be used, for example, to encode the motion of the interferometer, to provide very high speed autofocus or tip/tilt feedback, to create a color image of the object being measured, to automatically focus the system at different positions for different measurements conducted with different color sources, and to perform heterodyne interferometry with a single, vibration-immune measurement.

An optical fiber splitter device comprising at least two optical fibers of different lengths is disclosed for partial or complete compensation of the optical path difference between waves interfering to generate a hologram or an interferogram. Various implementations of this fiber splitter device are described in apparatuses for holographic and interferometric imaging of microscopic and larger samples.

An eye accommodation distance determining device is provided. The eye accommodation distance determining device includes an interferometer configured to generate a plurality of frequency modulated laser beams in different directions and to generate a plurality of interferometric signals using laser beams reflected from eye reflecting surfaces, a signal processer configured to generate a signal spectrum using each of said plurality of interferometric signals, a distance determiner configured to determine distances to the eye reflecting surfaces for each of said plurality of frequency modulated laser beams, a point coordinates determiner configured to determine coordinates of points on each of the eye reflecting surfaces for each of the laser beams, a reconstructor configured to generate an eye inner structure model based on the determined coordinates of points, and an eye accommodation distance determiner configured to determine, based on said eye inner structure model, an eye accommodation distance.

An interferometer system comprises a sample interferometer arm for guiding a first wave to a sample, and receiving a reflected wave from the sample and a phase amplifier for amplifying a phase shift of the reflected wave, to provide phase-shift-amplified intermediate wave. The interferometer system can also comprise an additional interferometer arm for guiding an additional wave to combine with the intermediate wave, to provide an output wave, and a detector for detecting the output wave.