A method and a system for determining relative position of an element of an optical system of an assembly for processing or measuring an object along a measurement line, involve generating a measurement beam and a reference beam of low coherence optical radiation. The measurement and reference beams, alternately or in combination, have a main beam and a multiplexed additional beam. The measurement beam, led toward the element of the optical system, and back-reflected, is superimposed on the reference beam in a region of common incidence of an interferometric optical sensor arrangement. Position or frequency of a main interference fringe pattern and an additional interference fringe pattern is detected.

An atomic beam is irradiated with a first laser beam, a second laser beam, and a third laser beam. The first laser beam and the third laser beam each have a wavelength corresponding to a transition between a ground state and a first excited state. The second laser beam has a wavelength corresponding to a transition between the ground state and a second excited state. First, atoms each having a smaller velocity component than a predetermined velocity in a direction orthogonal to the traveling direction of the atomic beam are changed from the ground state to the first excited state by the first laser beam. Subsequently, a momentum is provided for individual atoms in the ground state by the second laser beam, which removes the atoms from the atomic beam. Finally, atoms in the first excited state are returned from the first excited state to the ground state by the third laser beam.

An atomic beam is irradiated with a first, a second, and a third laser beam. The first laser beam and the third laser beam each have a wavelength corresponding to a transition between a ground state and a first excited state. The second laser beam has a wavelength corresponding to a transition between the ground state and a second excited state. First, atoms each having a smaller velocity component than a predetermined velocity in a direction orthogonal to the traveling direction of the atomic beam are changed from the ground state to the first excited state by the first laser beam. Subsequently, a momentum is provided for individual atoms in the ground state by the second laser beam, which removes the atoms from the atomic beam. Finally, atoms in the first excited state are returned from the first excited state to the ground state by the third laser beam.

The present invention provides a detection device and a detection method. The detection device comprises a light source module, a receiving module, an image generation module and a judgment module. The light source module is configured to emit light towards a film at a predetermined angle, the receiving module is configured to receive interference light formed by first reflected light reflected by an upper surface of the film and second reflected light reflected by a lower surface of the film, the image generation module is configured to generate an equal thickness interference fringe image according to the interference light, and the judgment module is configured to judge whether thickness of the film is uniform according to the equal thickness interference fringe image. The detection device can perform high accuracy detection on uniformity of the thickness of a film, thereby facilitating improving display quality of a display panel.

An atomic beam is irradiated with a first laser beam, a second laser beam, and a third laser beam. The first laser beam and the third laser beam each have a wavelength corresponding to a transition between a ground state and a first excited state. The second laser beam has a wavelength corresponding to a transition between the ground state and a second excited state. First, atoms each having a smaller velocity component than a predetermined velocity in a direction orthogonal to the traveling direction of the atomic beam are changed from the ground state to the first excited state by the first laser beam. Subsequently, a momentum is provided for individual atoms in the ground state by the second laser beam, which removes the atoms from the atomic beam. Finally, atoms in the first excited state are returned from the first excited state to the ground state by the third laser beam.

An optical system can include a mirror that reflects incoming light to a sensor for detection. The position and/or orientation of the mirror can be controlled to reflect incoming light from different locations and/or directions. Position and/or orientation of the mirror may be tracked and/or detected by an optical position sensor. The position sensor can transmit a beam to a reflector on the mirror, and the reflected beam can be received by the position sensor. Characteristics of the reflected beam can be measured to determine the position and/or orientation of the mirror. For example, the beam can be used for interferometric and/or intensity measurements, which can then be correlated with a position and/or orientation of the mirror.

A measurement system includes a light source configured to emitting a source light, a detection platform configured to support a reference sample and a test sample; a light guiding element on an optical path of the source light; and a detector. The detection platform is configured to synchronously move the reference sample and the test sample on a same surface of the detection platform. The light guiding element is configured to divide the source light into a measurement light and a reference light and guide the measurement light to the test sample, and the reference light to the reference sample. The measurement light reflected by the test sample and the reference light reflected by the reference sample are combined as an interference light. The detector is configured to receive the interference light and obtain optical information of the test sample according to the interference light.

A measurement apparatus for measuring a thickness of a semiconductor wafer includes: an optical system configured to perpendicularly irradiate a sample wafer and a reference wafer with light, and receive interference signals of the light reflected on front and back surfaces of the respective wafers; a signal processor configured to perform frequency analysis of the interference signals received by the optical system to obtain peak positions of a point spread function of the respective wafers; and a calculator configured to calculate a thickness “tsample” of the sample wafer based on the peak position “x” of the sample wafer and the peak position “y” of the reference wafer obtained by the signal processor, and a thickness “treference” of the reference wafer.

An interferometer detection system, including a beam splitter receiving a collimated light signal and splitting the signal into a first light signal and a second light signal. The system includes a first mirror receiving and reflecting the first light signal along a first path. The system includes a second mirror receiving and reflecting the second light signal along a second path via a transparent material. The system includes a 2D photosensor array configured to receive from the beam splitter the reflected first light signal merged with the reflected second light signal double passing through the transparent material and configured to generate an interference fringe pattern. A non-sinusoidal interference fringe pattern indicates geometrical variation between a wavefront of the reflected first light signal along the first path and a wavefront of the reflected second light signal double passing through the transparent material along the second path.

A measurement system includes a light source configured to emitting a source light, a detection platform configured to support a reference sample and a test sample; a light guiding element on an optical path of the source light; and a detector. The detection platform is configured to synchronously move the reference sample and the test sample on a same surface of the detection platform. The light guiding element is configured to divide the source light into a measurement light and a reference light and guide the measurement light to the test sample, and the reference light to the reference sample. The measurement light reflected by the test sample and the reference light reflected by the reference sample are combined as an interference light. The detector is configured to receive the interference light and obtain optical information of the test sample according to the interference light.