A measurement method for interferometrically measuring the shape of a surface (112) of a test object (114). A test wave (125-1, 125-2) directed at the test object has a wavefront that is at least partially adapted to the desired shape of the surface, and a reference wave (128-1, 128-2) directed at a reflective optical element (130-1, 130 2) has a propagation direction that deviates from the propagation direction of the test wave (125-1, 125-2) for each of two input waves by diffraction at a diffractive element (124). For each wavelength, the test wave is superimposed after interaction with the test object with the associated reference wave after the back-reflection at the first reflective optical element. The test and reference waves are diffracted again at the diffractive element for superposition. An interferogram produced by the superposition is captured in a capture plane (148-1, 148-2). The interferograms are jointly evaluated.

A super-resolution holographic microscope includes a light source configured to emit input light, a diffraction grating configured to split the input light into first diffracted light and second diffracted light, a mirror configured to reflect the first diffracted light, a wafer stage arranged on an optical path of the second diffracted light and on which a wafer is configured to be arranged, and a camera configured to receive the first diffracted light that is reflected by the mirror and the second diffracted light that is reflected by the wafer to generate a plurality of hologram images of the wafer.

An interferometer has a first input configured to provide a first measurement beam at a first frequency, and a second measurement signal at the first frequency. The interferometer has a second input configured to provide a reference beam at a second frequency that is different than the first frequency; an optical element comprising a first portion comprising a polarization beam splitter; and a diffraction grating disposed over the optical element configured to diffract the first measurement beam and the second measurement beam

The present invention is directed to the provision of an interferometer and a phase shift amount measuring apparatus that can precisely operate in the EUV region. The interferometer according to the invention comprises an illumination source for generating an illumination beam, an illumination system for projecting the illumination beam emitted from the illumination source onto a sample, and an imaging system for directing the reflected beam by the sample onto a detector. The illumination system includes a first diffraction grating for producing a first and second diffraction beams which respectively illuminate two areas on the sample where are shifted from each other by a given distance, and the imaging system includes a second grating for diffracting the first and second diffraction beams reflected by the sample to produce a third and fourth diffraction beams which are shifted from each other by a given distance.

A compensation optical unit (30) for a measurement system (10) for determining a shape of an optical surface (12) of a test object (14) by interferometry generates a measuring wave (44), directed at the test object, with a wavefront that is at least partly adapted to a target shape of the optical surface from an input wave (18). The unit includes first (32) and second (34) optical elements disposed in a beam path of the input wave. The second optical element is a diffractive optical element configured to split the input wave into the measuring wave and a reference wave (42) following an interaction with the first optical element. At least 20% of a refractive power of the entire compensation optical unit is allotted to the first optical element, and this allotted refractive power has the same sign as the refractive power of the entire compensation optical unit.

The optical angle sensor comprises a diffraction unit, a light source, a light receiving unit, and a plurality of reflection units. The diffraction unit includes a first diffraction part for generating combined light and a second diffraction part for diffracting a first light and a second light a plurality of times. The plurality of reflection units includes a first reflection unit, a second reflection unit, a third reflection unit that reflects the first light and the second light through the second diffraction part toward the second diffraction part, fourth reflection unit, and fifth reflection unit. The calculating unit, with the rotation of the diffraction unit, calculates the amount of change in the angle based on the change in the interference signal caused by the combined light generated on the light receiving surface.

The disclosure provides a microphone chip, a microphone, and a terminal device. The microphone chip includes a substrate and a diaphragm that are disposed oppositely, a reflector located on a side that is of the diaphragm and that is close to the substrate, a grating group located between the substrate and the diaphragm, and an optical emitter and an optical detector that are located between the substrate and the grating group. The grating group includes a plurality of gratings, and distances between at least two gratings in the plurality of gratings and the reflector are different.

A field detector (2) comprises a field-responsive element (10) which undergoes a dimensional change when exposed to a predetermined field; and an interferometric read-out arrangement arranged to detect the dimensional change of the field-responsive element. A light source (4) is arranged to provide a measurement beam reflected from the field-responsive element (10) and a reference beam not reflected from the field-responsive element (10), an optical detector (6) being disposed so as to detect at least part of an interference pattern produced by the measurement beam and the reference beam. The field-responsive element (10) has a shape comprising a curved surface and is constrained at least one edge (12) thereof such that the dimensional change causes the curved surface to be displaced in a direction which changes an optical path length of the measurement beam relative to the reference beam, thereby changing the interference pattern detected by said optical detector.

Measurement method for interferometrically determining a shape of a test object (14) surface (12) includes arranging a first diffractive optical element (30, 130, 230) in an input wave (18) beam path, to generate a first test wave (34) with a wavefront that is adapted to a desired shape of the optical surface, detecting a first interferogram generated by the first test wave after interaction with the test object surface, arranging a different diffractive optical element (32, 232) in the input wave beam path for generating a further test wave with a wavefront which is adapted to the desired shape of the optical surface, the first and the further diffractive optical elements differing in their respective diffraction structure configurations, capturing a further interferogram generated by the further test wave after interaction with the test object surface, and determining the surface shape of the test object by calculating the two interferograms.

A system for precision displacement measurement based on a self-traceable grating interference includes a coherent light source, a photoelectric detection module, a self-traceable grating and a signal processing module. The self-traceable grating is arranged on a to-be-measured displacement motion platform. The coherent light source, the photoelectric detection module and the signal processing module are sequentially connected. Laser generated by the coherent light source propagates through the photoelectric detection module and is incident on the self-traceable grating, diffracts with the self-traceable grating, returns to the photoelectric detection module to continue propagating and enters the signal processing module. The signal processing module collects an interference signal to obtain a motion displacement and a motion direction.