476 results about "Reference mirror" patented technology

The illumination profile of a radiation beam is initially measured using a CCD detector. A reference mirror is then placed in the focal plane of the high aperture lens and the reflected radiation measured. By comparing the illumination profile and the detected radiation it is possible to determine the transmission losses for S and P polarisation which can then be used in scatterometry modeling.

A laser interferometer is embedded into an interference microscope to precisely determine the in-focus position of the microscope objective's reference mirror. A collimated laser beam is introduced into the microscope system and split into two beams directed toward a calibration reference surface and the interference objective. The light reflected from the calibration reference surface is returned to the camera. The light into the interference objective is focused onto the reference mirror and returned to the camera. For the purpose of calibration, the two beams are combined at the camera to produce interference fringes. When the reference mirror is in focus, the returned beam is collimated; if the mirror is on either side of focus, the beam is either converging or diverging. Accordingly, the interferogram produced at the camera reflects the in-focus or out-of-focus condition of the reference mirror. The curvature of the wavefront returned from the reference mirror is determined electronically by analyzing the interference fringes produced with the beam returned from the calibration reference surface. By minimizing the curvature of the reference-mirror wavefront as the mirror is translated along the optical path, the reference mirror can be focused with an accuracy greater than possible by visual observation. Furthermore, by automating the focusing system with a precise translation mechanism driven by closed-loop control, operator-to-operator variations are completely eliminated.

An oxygen concentration measurement system for blood hemoglobin comprises a multiple-wavelength low-coherence optical light source that is coupled by single mode fibers through a splitter and combiner and focused on both a target tissue sample and a reference mirror. Reflections from both the reference mirror and from the depths of the target tissue sample are carried back and mixed to produce interference fringes in the splitter and combiner. The reference mirror is set such that the distance traversed in the reference path is the same as the distance traversed into and back from the target tissue sample at some depth in the sample that will provide light attenuation information that is dependent on the oxygen in blood hemoglobin in the target tissue sample. Two wavelengths of light are used to obtain concentrations. The method can be used to measure total hemoglobin concentration [Hb.sub.deoxy +Hb.sub.oxy ] or total blood volume in tissue and in conjunction with oxygen saturation measurements from pulse oximetry can be used to absolutely quantify oxyhemoglobin [HbO.sub.2 ] in tissue. The apparatus and method provide a general means for absolute quantitation of an absorber dispersed in a highly scattering medium.

Guidance systems for guiding a catheter through tissue within a body are described. In one form, the system is implemented in connection with a catheter which includes a catheter body having a optic fibers extending between a first end and a second end thereof. The guidance system is coupled to the catheter body and includes a first optic fiber, a second optic fiber, and a detecting element. The first optic fiber includes a first end and a second end, and is coupled to the catheter body so that the first optic fiber second end is adjacent the catheter second end. The second optic fiber also includes a first end and a second end, and a reference mirror is positioned adjacent the second optic fiber second end. The first optic fiber first end is communicatively coupled to the detecting element and the second optic fiber first end is communicatively coupled to the detecting element. The detecting element is configured to determine interference between a light beam propagating through the first optic fiber and a light beam propagating through the second optic fiber.

In one embodiment, the present invention provides an interferometric inspection system for inspecting semiconductor samples. The system includes at least one illumination source for generating an illumination beam and an interferometric microscope module for splitting the illumination beam into a test beam directed to the semiconductor sample and a reference beam directed to a tilted reference mirror. The beams are combined to generate an interference image at an image sensor. The tilted reference mirror is tilted at a non-normal angle with respect to the reference beam that is incident on the mirror to thereby generate fringes in the interference image. The system also includes an image sensor for acquiring the interference image from the interferometric microscope module and generates an inherence signal. The system further includes a processing module configured to generate complex field information corresponding to the sample from the interference image signal and an alignment module located in the optical path between the interferometric module and the image sensor. In another embodiment, the processing module is configured to generate complex field information from either spatial fringe analysis or temporal fringe analysis performed on the interference image signal.

The invention discloses a method and a cloud system for realizing virtual machine migration. The method comprises the following steps that a sharing storage server creates a sharing content for storing a reference mirror image and an increment mirror image, a physical machine is adopted for mounting, and the physical machine copies the reference mirror image of a virtual machine to be migrated from the sharing content during the migration of the virtual machine; a source physical machine selects a target physical machine and sends pre-migration request information to the target physical machine; the target physical machine judges whether the virtual machine migration is allowed or not; when the target physical machine allows the virtual machine migration, the source physical machine monitors local internal memory data change, and a circulation copying mode is adopted for migrating the virtual machine to the target physical machine; the target physical machine starts the virtual machine and monitors whether the virtual machine normally operates or not; when the virtual machine normally operates, the virtual machine migration is successful, otherwise, the virtual machine migration is failed, and the operation of the virtual machine is recovered at the source physical machine. The embodiment of the invention has the advantages that the virtual machine migration process can be fast completed on the premise of not influencing the use of users, and in addition, the migration success rate is high.

The present invention is directed to an ophthalmologic measurement method which can depict three-dimensional structures of the interfaces of an eye by short-coherence interferometry based on reference points. For this purpose, the pupil is illuminated at a plurality of points by a short-coherence illumination source. The measurement beam reflected at these points by the interfaces and surfaces of the eye is superimposed with a reference beam. The measurement data which are generated in this way are spectrally split by a diffraction grating, imaged on a two-dimensional detector array and conveyed to a control unit which determines a three-dimensional structure of all intraocular interfaces and surfaces of the eye. In the suggested Fourier domain OCT method, the depiction of three-dimensional structures is preferably carried out by spline surfaces or polygon surfaces. In doing so, it is possible to determine the depth positions of the measurement beams in many points of the pupil with a single recording of the array camera in that the pupils are illuminated by a diaphragm grid and the reference mirror contains a periodic phase grid.

An optical image measuring device which can form a highly reliable image even if an object moves during scanning of a signal light is provided. An optical image forming device 1 comprises: an interferometer that splits a low coherence light L0 into a signal light LS and a reference light LR and generates an interference light LC by overlaying the signal light LS reflected by a fundus oculi with the reference light LR reflected by a reference mirror 14; a CCD 34 which receives the interference light LC and outputs a detection signal; Galvanometer mirrors 22 and 23 to scan the signal light LS in a main scanning direction and a sub-scanning direction; and a computer 40 forming tomographic images G1 to Gm along the main scanning direction at different positions of the sub-scanning direction. The Galvanometer mirrors 22 and 23 scan the signal light LS in a given direction crossing the main scanning direction, and the computer 40 forms a tomographic image for correction GR along the given direction to correct displacement of each topographic image Gi based on the tomographic image for correction GR.

Provided is an optical image measuring apparatus forming a three-dimensional image based on tomographic images of an object, acquired at various depths even when the object moves during measurement. Including a half mirror (6) for dividing a light beam signal light (S) and reference light (R), a frequency shifter (8), a reference mirror (9) and a piezoelectric element (9A) used to change an optical path length of the reference light (R), CCDs (21, 22) for receiving interference light beams (L) resulting from interference light produced by superimposing the signal light (S) and the reference light (R) on each other by the half mirror (6) and outputting detection signals, an image forming portion for forming tomographic images based on the detection signals, a measurement depth calculating means (53), and an image processing portion (57). Forming a three-dimensional image or the like based on the arranged tomographic images.

A device (10) and methods for simultaneously measuring the thickness of individual wafer layers, the depth of etched features on a wafer, and the three-dimensional profile of a wafer. The structure of the device (10) is comprised of a source/receiver section (12) having a broadband source (14), a receiver (16) and a signal processing section (20). An interferometer (28) separates or combines measurement and reference light and has a measurement leg (30) and a reference leg (34), and a reference mirror (36). The device (10) analyzes a received spectrum which is comprised of a measurement of intensity versus wavelength. There are two measurement methods disclosed: the first method is utilized for taking a single measurement and the second method is utilized for multiple measurements.

The invention discloses precise assembling and adjusting device and method for a detector chip of an imaging system. The assembling and adjusting device comprises a movement control system, a detection system, an accessory structure and a computer; the movement control system is composed of a translation stage, a revolving stage and a tilting table and used for adjusting the spatial positions of a device to be detected and the detection system; the detection system is composed of an autocollimation and a telecentric digital microimaging system and used for measuring the angle and positional deviation of the device to be detected; and the compute is able to control the movement of the translation stage and record the position coordinates and can also be used for acquiring an image of the device to be detected from the telecentric digital microimaging system and analyzing and calculating. The assembling and adjusting method includes the assembling and adjusting of a reference mirror, the transmission of the angle and position of the detector chip, and the assembling and adjusting of the detector chip; the measurement precision of the angle and position respectively reaches second level and micro dimension during the assembling and adjusting; and the deviation of angle and position of the detector chip can be respectively less than 1 and 0.02mm after the assembling and adjusting.

Provided is an optical image measuring apparatus capable of effectively receiving interference light, particularly an alternating current component thereof using a smaller number of photo sensors. The optical image measuring apparatus includes a polarizing plate for converting a light beam from a broad-band light source to linearly polarized light, a half mirror for dividing the light beam into signal light and reference light, a piezoelectric element for vibrating a reference mirror, a wavelength plate for converting the reference light to circularly polarized light, a polarization beam splitter for extracting two different polarized light components from interference light produced from the signal light and the reference light which are superimposed on each other by the half mirror, CCDs for detecting the two different polarized light components, and a signal processing portion for producing an image of an object to be measured based on the detected polarized light components. A frequency for intensity modulation of the light beam is synchronized with a beat frequency of the interference light. A frequency of vibration of the reference mirror is synchronized with the beat frequency of the interference light and an amplitude of vibration thereof is set to be equal to or smaller than a wavelength of the interference light.

The invention relates to a device and a method for measuring synchronous phase shifting interference of a Fizeau quasi-common optical path structure. The device comprises a laser, a half wave plate, a focusing lens, a spatial filter, a circularly polarized light beam splitter (an optically active crystal), a spectroscope, a collimating lens, a reference mirror, a pin-hole diaphragm, an imaging lens, a light splitting and phase shifting system, a computer control system and a CCD camera. According to the device and the method disclosed by the invention, a synchronous phase shifting technology is combined with a Fizeau interference method, so that technical difficulties of a conventional interferometer in poor stability and disability of realizing dynamic measurement are solved; the device and the method are characterized by utilizing an optical rotation effect of the crystal and adding the circularly polarized light beam splitter with a very small splitting angle in the Fizeau interfering structure, so as to realize orthogonally polarized separation of reference lights and test lights in a common optical path. The device and the method disclosed by the invention avoid utilization of a high-quality quarter wave plate in a synchronous phase-shifting interference system, and also greatly decrease a phase measurement error caused by a stress birefrigent effect which exists in an optical element of the system.

An improved lithographic interferometer system, is presented herein. The lithographic interferometer system comprises a beam generating mechanism, mirrors which reflect those beams, and detection devices for detecting an interference pattern of overlapping reflected beams. The beam generating mechanism comprises a beam-splitter, which splits the beams into reference beams and measuring beams, a reference mirror that provides a plane mirror interferometer, and a reflective surface that emits at least one reference beam used in a differential plane mirror interferometer.

Provided is an optical image measuring apparatus capable of easily changing a scanning interval of an object to be measured in a depth direction with high precision. The apparatus includes an interference optical system for superimposing signal light propagating through the object to be measured on reference light subjected to frequency shift to produce interference light, a reference mirror driving unit for driving a mirror to scan the object to be measured in the depth direction, shutters for sampling interference light beams, CCDs for storing charges for only a predetermined storage time and outputting electrical signals, a control unit for changing the storage time of the CCDs, a signal processing portion for calculating intensities and phases of interference light beams corresponding to each depth of the object to be measured which are successively detected by the CCDs during scanning based on the electrical signals successively outputted from the CCDs every changed storage time, and a setting operation unit for setting the storage time of the CCDs by an operator.

A fundus observation device which can simultaneously capture both surface images and tomographic images of the fundus oculi is provided. The fundus observation device 1 has a fundus camera unit 1A, an OCT unit 150, and an arithmetic and control unit 200. The fundus camera unit 1A has an illuminating optical system 100 and an imaging optical system 120. The arithmetic and control unit 200 forms the surface image of fundus oculi Ef based on signals from fundus camera unit 1A. The OCT unit 150 divides low coherence light LO into the signal light LS and the reference light LR, and detects the interference light LC that can be obtained from the signal light LS passing through fundus oculi Ef and the reference light LR passing through reference mirror 174. The arithmetic and control unit 200 forms tomographic images of fundus oculi Ef based on these detecting results. A Dichroic mirror 134 combines the optical path of the signal light LS toward fundus oculi Ef into the optical path for imaging of the imaging optical system 120, and separates the optical path of the signal light LS towards fundus oculi Ef from the optical path for imaging.

An integrated interferometric and intensity based microscopic inspection system inspects semiconductor samples. A switchable illumination module provides illumination switchable between interferometric inspection and intensity based microscopic inspection modes. Complex field information is generated from interference image signals received at a sensor. Intensity based signals are used to perform the microscopic inspection. The system includes at least one illumination source for generating an illumination beam and an integrated interferometric microscope module for splitting the illumination beam into a test beam directed to the semiconductor sample and a reference beam directed to a tilted reference mirror. The beams are combined to generate an interference image at an image sensor. The tilted reference mirror is tilted with respect to the reference beam that is incident on the mirror to thereby generate fringes in the interference image. The system also includes an image sensor for acquiring the interference image from the inteferometric microscope module and intensity signals from the microscopic inspection image.

Calibration of an angularly resolved scatterometer is performed by measuring a target in two or more different arrangements. The different arrangements cause radiation being measured in an outgoing direction to be different combinations of radiation illuminating the target from ingoing directions. A reference mirror measurement may also be performed. The measurements and modeling of the difference between the first and second arrangements is used to estimate separately properties of the ingoing and outgoing optical systems. The modeling may account for symmetry of the respective periodic target. The modeling typically accounts for polarizing effects of the ingoing optical elements, the outgoing optical elements and the respective periodic target. The polarizing effects may be described in the modeling by Jones calculus or Mueller calculus. The modeling may include a parameterization in terms of basis functions such as Zernike polynomials.

A high-precision splitting sub-mirror relative inclining error photoelectric detection system comprises the following components: a HE-NE laser, a spatial filter, a collimator objective, a cubic beam splitting prism, a detected splitting sub-mirror set, a reference mirror, a light path beam-contracting system, a CCD planar array photoelectric detector and a data processing system. The HE-NE laser, the spatial filter and the collimator objective form a light source arm part of the detection system together. The detected splitting sub-mirror set forms a measuring arm part of the detection system. The reference reflecting mirror forms a reference arm part of the detection system. The relative inclining error information which is detected by the detecting arm and is between the splitting sub-mirrors is detected by the CCD planar array photoelectric detector. The detected interference image information is processed by a data processing system for real-time detecting the inclining error between the splitting sub-mirrors. The invention can execute a real-time high-precision detection. The effect of the relative inclining error between the sub-mirrors to the imagining quality of the telescope can be reduced with a large scale and the invention has the advantage of simple structure.

The present invention provides a measuring apparatus which measures a shape of a surface of a measurement target object, comprising a light projecting optical system configured to split light from a light source into measurement light and reference light so that the measurement light enters the surface of the measurement target object and the reference light enters a reference mirror, a light receiving optical system configured to guide the measurement light reflected by the surface of the measurement target object and the reference light reflected by the reference mirror to a photoelectric conversion device, and a processing unit configured to calculate the shape of the surface of the measurement target object based on an interference pattern which is detected by the photoelectric conversion device and formed by the measurement light and the reference light.

A method capable of accurately measuring a physical quantity of a measurement object in a substrate processing apparatus. In a temperature measurement apparatus for implementing the method, two interference positions are measured at different timings when a reference mirror is caused to move in the direction away from a collimator fiber, and a difference between the two interference positions is calculated. When the reference mirror remote from the collimator fiber is caused to move toward the collimator fiber, two interference positions are measured at different timings, and a difference between the two interference positions is calculated. An average value of the interference position differences is calculated, an optical path length difference is determined from the average value, and a wafer temperature is calculated from the optical path length difference.

Provided is an optical image measuring apparatus capable of effectively obtaining a signal intensity of interference light and phase information thereof by improving detection sensitivity. The optical image measuring apparatus includes a broad-band light source for outputting a light beam whose intensity is periodically modulated, a polarizing plate for converting the light beam to linearly polarized light, a half mirror for dividing the light beam into signal light and reference light and superimposing the signal light and the reference light on each other to produce interference light, a wavelength plate for converting the reference light to circularly polarized light, a frequency shifter for shifting a frequency of the reference light, a reference mirror which is moved by a piezoelectric element, a polarization beam splitter for extracting an S-polarized light component and a P-polarized light component from the interference light, CCDs for detecting the respective polarized light components and outputting detection signals, and a signal processing portion for calculating a signal intensity of the interference light and a phase thereof based on the detection signals. An image of an object to be measured is formed based on a result obtained by calculation.