Abstract: An inertial sensor consisting of an electrodynamic trap for suspending one or more charged particles and a readout device for measuring variations in the position or motion of the particles when the trap is subjected to acceleration forces. Particle may be measured by optical interferometry, optical leverage, resonant electric field absorption, or by producing an image of the particle motion and processing the image data to obtain values representing the acceleration forces on the trap in one to six degrees of freedom. The electrodynamic trap employs electrodes to which a time-varying potential are applied to produce a quadupole field that constrains the charged particles to a specific location between said electrodes by a substantially linear, tunable restoring force.

Abstract: A method and a device are provided for estimating at least one component placement position on a substrate at which a component is to be placed. The component placement position is estimated on the basis of the position of at least one mark on the substrate. The statistical measurement inaccuracies of the marks are determined. Subsequently, the positional accuracy of the component placement position on the substrate is estimated on the basis of the measurement inaccuracies of the marks. Subsequently, the estimated positional accuracy of the component placement position is compared with a desired positional accuracy. Subsequently, a determination is made regarding whether the component is to be placed on the substrate with the estimated positional accuracy of the component placement position.

Abstract: Low-power, low flow-rate, portable, miniaturized plasma devices are provided. A portable, low-power, low flow-rate, miniaturized sample introduction device is also provided. The devices are inexpensive to make, have low operating cost and can be used with a variety of gases and gas mixtures. The devices can be used for elemental analysis from liquid or solid micro-samples by optical emission or mass spectrometry provided that an appropriate sample introduction system is used.

Abstract: A structure formed on a semiconductor wafer is examined by obtaining a first diffraction signal measured from the structure using an optical metrology device. A first profile is obtained from a first machine learning system using the first diffraction signal obtained as an input to the first machine learning system. The first machine learning system is configured to generate a profile as an output for a diffraction signal received as an input. A second profile is obtained from a second machine learning system using the first profile obtained from the first machine learning system as an input to the second machine learning system. The second machine learning system is configured to generate a diffraction signal as an output for a profile received as an input. The first and second profiles include one or more parameters that characterize one or more features of the structure.

Abstract: An optical pulse evaluation device and an in-service optical pulse evaluation device is disclosed which are capable of characteristics evaluation of an optical pulse itself or a sample launched therein in a relatively high bit-rate region. The optical pulse evaluation device evaluates a pulse waveform expressing an optical intensity of the optical pulse, an instantaneous frequency of the optical pulse, or a modulated light prepared by modulating the optical pulse in a light source end. The optical pulse evaluation device also observes a waveform change after a known optical pulse is passed through a device such as an optical fiber to evaluate a waveform deterioration or a compensation behavior caused by the device. The in-service optical pulse evaluation device is capable of measuring a wavelength dispersion in an optical communication.

Abstract: A spectroscopic sensor apparatus based on an all optical fiber platform includes a light source, a sensor head, and a fiber acousto-optic tunable filter (FAOTF) based spectrometer. The target agent to be detected interacts with the optical field through the sensor head and produces an absorption or emission spectrum. The absorption or emission spectrum is then measured by the AOTF spectrometer to analyze the constituent of the target agent.

Abstract: The present invention provides methods and apparatuses that can improve measurement accuracy in interferometers. The invention provides methods for determining digital compensation filters that measure a frequency response or responses to be compensated, and then determining a filter target response from the inverse of the frequency response or responses. A digital compensation filter can be determined from the filter target response using a discrete sum of cosines with a phase argument. The invention also allows other desired filter responses to be integrated into the filter target response before determining the digital compensation filter.

Abstract: Disclosed is a system including: (i) an interferometer configured to direct test electromagnetic radiation to a test surface and reference electromagnetic radiation to a reference surface and subsequently combine the electromagnetic radiation to form an interference pattern, the electromagnetic radiation being derived from a common source; (ii) a multi-element detector; and (iii) one or more optics configured to image the interference pattern onto the detector so that different elements of the detector correspond to different illumination angles of the test surface by the test electromagnetic radiation.

Abstract: An apparatus for optical measurement of an object, especially for measuring movement, is provided, which includes an interferometer for measuring movements along the measurement beam of the interferometer, as well as a confocal auto-focus microscope. The interferometer is coupled in the beam path of the confocal auto-focus microscope, such that the measurement beam of the interferometer is simultaneously the focusing beam of the microscope. Here, it is guaranteed that the interferometric movement measurement is always performed at the focal point of the microscope that is used. This enables automatic correction of the Guoy effect for objectives with high numerical aperture. In addition, for the use of a scanning confocal auto-focus microscope, data sets of test objects can also be measured, which comprise their vibrational behavior, height profile, and optionally also their in-plane movement behavior.

Abstract: An apparatus and method for measuring displacement includes a light beam directed to an interferometer core that splits the light beam into first and second component beams. The first component beam is directed to a diffraction grating at approximately a Littrow angle. A diffraction is received by the interferometer core and is combined with the second component beam. The combination of the first and second component beams is measured to determine displacement of the diffraction grating.

Abstract: A interferometer-based fouling detection system and method are described. The system may include a fiber optic cable, a light source in communication with the fiber optic cable, at least one photo detector in communication with the fiber optic cable, and at least one interferometric spectrometer. The fiber optic cable may include a long period grating and a fiber Bragg grating or it may include a facet edge. The system may instead include a fiber optic cable, a light source in communication with the fiber optic cable, at least one photo detector in communication with the fiber optic cable, a fiber coupler, a reference probe including a mirror, a sample probe, and an interferometer.

Abstract: A measurement method measures a wavefront aberration of a target optical system using an interference pattern formed by lights from first and second image side slits. The first image side slit has a width equal to or smaller than a diffraction limit of the target optical system. The measurement method includes the steps of obtaining a first and second wavefronts having wavefront aberration information of the target optical system in ±45° directions relative to the polarization direction of the light, and calculating wavefront aberration of the target optical system based on the first and second wavefronts of the target optical system obtained by the obtaining step.

Abstract: A micro-optical fiber tip based sensor system for pressure, acceleration, and pressure gradient measurements in a wide bandwidth, the design of which allows for multiplexity of the input side of the system is based on micro-electromechanical fabrication techniques. The optical portion of the system is based on low coherence fiber-optic interferometry techniques which has a sensor Fabry-Perot interferometer and a read-out interferometer combination that allows a high dynamic range and low sensitivity to the wavelength fluctuation of the light source. A phase modulation and demodulation scheme takes advantage of the Integrated Optical Circuit phase modulator and multi-step phase-stepping algorithm for providing high frequency and real time phase signal demodulation. The system includes fiber tip based Fabry-Perot sensors each of which has a diaphragm that is used as a transducer.

Abstract: A Fabry-Perot cavity filter includes a first mirror and a second mirror. A gap between the first and the second mirror monotonically varies as a function of width of the filter. This filter may be used with photodetector and a channel selection filter in an optical device, such as a spectrum analyzer. The channel selection filter may be a metal nanooptic filter array which includes plurality of subwavelength apertures in a metal film or between metal islands.

Abstract: An interferometric optical analyzer apparatus comprises a light source, an interferometer and a detection system for determining the linear response, and subsequently any optical parameter, of one or more optical elements using substantially unpolarized light. In one embodiment, the light source supplies substantially unpolarized coherent light over a predetermined range of optical frequencies. The optical element is coupled in one arm of the interferometer and the other arm of the interferometer is used as a reference. The unpolarized light is first passed through the interferometer then through a three-way polarization splitter unit to split the light into at least three light beams according to preselected polarization axes corresponding to three linearly independent states of polarization. The three light beams are coupled to individual detectors and a controller computes Jones matrix elements from the resulting electrical signals.

Abstract: Common path frequency domain optical coherence reflectometry/tomography devices with an additional interferometer are suggested. The additional interferometer offset is adjusted such, that it is ether less than the reference offset, or exceeds the distance from the reference reflector to the distal boundary of the longitudinal range of interest. This adjustment allows for relieving the requirements to the spectral resolution of the frequency domain optical coherence reflectometry/tomography engine and/or speed of the data acquisition and processing system, and eliminates depth ambiguity problems. The new topology allows for including a phase or frequency modulator in an arm of the additional interferometer improving the signal-to-noise ratio of the devices. The modulator is also capable of substantially eliminating mirror ambiguity, DC artifacts, and autocorrelation artifacts. The interference signal is produced either in the interferometer or inside of the optical fiber probe leading to the sample.

Abstract: Systems, methods and sensors detect changes in incident optical radiation. Current is driven through one or more active areas of a detector while the incident optical radiation illuminates the active areas. Voltage is sensed across one or more of the active areas, a change in the voltage being indicative of the changes in incident optical radiation.

Abstract: In a method for improving imaging properties of an illumination system or a projection objective of a microlithographic projection exposure apparatus, which comprises an optical element having a surface, the shape of the surface is measured directly at various points. To this end, a measuring beam is directed on the points, and the reflected or refracted beam is measured, e.g. using an interferometer. Based on deviations of the measured shape from a target shape, corrective measures are derived so that the imaging errors of the optical system are improved. The corrective measures may comprise a change in the position or the shape of the optical element being analyzed, or another optical element of the optical system. The target shape of the surface may, for example, be determined so that the optical element at least partially corrects imaging errors caused by other optical elements.

Abstract: Systems and methods are described for faster processing of multiple spatially-heterodyned direct to digital holograms.

Abstract: A signal conditioning module provides a polarimeter capability in a photometric system. The module may include multiple variable delay polarization modulators. Each modulator may include an input port, and a first arm formed to include a first reflector and first rooftop mirror arranged in opposed relationship. The first reflector may direct an input radiation signal to the first rooftop mirror. Each modulator also may include an output port and a second arm formed to include a second reflector and second rooftop mirror arranged in opposed relationship. The second reflector can guide a signal from the second rooftop mirror towards the output port to provide an output radiation signal. A beamsplitting grid may be placed between the first reflector and the first rooftop mirror, and also between the second reflector and the second rooftop mirror. A translation apparatus can provide adjustment relative to optical path length vis-a-vis the first arm, the second arm and the grid.