Abstract: The present disclosure relates generally to ion implantation, and more particularly, to systems and processes for measuring the temperature of a wafer within an ion implantation system. An exemplary ion implantation system may include a robotic arm, one or more load lock chambers, a pre-implantation station, an ion implanter, a post-implantation station, and a controller. The pre-implantation station is configured to heat or cool a wafer prior to the wafer being implanted with ions by the ion implanter. The post-implantation station is configured to heat or cool a wafer after the wafer is implanted with ions by the ion implanter. The pre-implantation station and/or post-implantation station are further configured to measure a current temperature of a wafer. The controller is configured to control the various components and processes described above, and to determine a current temperature of a wafer based on information received from the pre-implantation station and/or post-implantation station.

Abstract: An apparatus for reducing a chromatic spread angle of light diffracted at an acousto-optic element includes the acousto-optic element and a first and a second focusing optical unit. The acousto-optic element is disposed in a beam path of an incident light beam and is configured to generate the diffracted light from the incident light beam such that the diffracted light emanates from a virtual interaction point of the acousto-optic element. The first focusing optical unit is disposed in the beam path upstream of the acousto-optic element and the second focusing optical unit is disposed in the diffracted light such that a focus of the incident light beam is situated downstream of the first focusing optical unit in the acousto-optic element and the virtual interaction point is located in a front focus of the second focusing optical unit.

Abstract: A measuring apparatus includes a holding unit and a measuring unit. The measuring unit includes a first optical fiber for transmitting light emitted from a light source, a branching member for branching the light transmitted through the first optical fiber to at least two measuring optical fibers, a plurality of heads including respective beam condensers for converging the light branched by the branching member onto a measurand, a shutter device for shifting timings of application of the light applied from the heads to the measurand, a second optical fiber branched from the branching member and transmitting returning light reflected from the measurand, a spectroscopic unit having a light detector for detecting the returning light, and a controller for controlling the shutter device to control the timings of application of the light applied from the heads to the measurand and controlling the light detector to detect the returning light individually.

Abstract: Techniques for using ferroelectric liquid crystals Dammann grating (FLCDG) for light detection and ranging devices are disclosed. In LiDAR devices, accuracy, response time, and cost performance can be limited by some factors, such as laser pulse width, time resolution of a time-to-digital conversion chip, detector bandwidth, shot noise, and time error generated by electronic circuits. A FLCDG-based architecture can improve a LiDAR device, and provide for one-shot capturing due to the high switching speed at very low driving voltage provided by ferroelectric liquid crystals and the equal diffracting ability of Dammann grating.

Abstract: A method includes: transmitting an incident light to an object located on a stage, in which a first light and a second light are reflected; receiving the first light and the second light by an imaging lens group to obtain a third pattern corresponding to the first pattern and a fourth pattern corresponding to the second pattern; transmitting the third pattern and the fourth pattern to an image sensor, in which a center point of the third pattern and a center point of the fourth pattern are separated by a first distance on the image sensor; calculating a tilted angle between an optical axis of the imaging lens group and a normal direction of the stage according to the first distance; and adjusting the stage according to the tilted angle such that the normal direction is parallel to the optical axis.

Abstract: A system for correcting phase noise and/or drift, the system includes an optical signal module being capable of amplitude modulating the optical signal while being phase- and/or frequency-shifted. Further, the system includes a beam splitter capable of separating at least backward travelling waves based on polarization. Moreover, a fiber connected to the beam splitter and a polarization rotator capable of changing the polarization of the optical signal are provided. The system has a partially reflecting reflector capable of creating a backward travelling wave as well as a photodiode capable of receiving the backward travelling wave. The photodiode is capable of generating a detection signal used for detecting phase noise and/or drift in the backward travelling wave.

Abstract: A quantitative phase microscopy (QPM) system and methods are provided for sample imaging and metrology in both transmissive and reflective modes. The QPM system includes a first illuminating beam propagating along a transmission-mode path and a second illuminating beam propagating along a reflection-mode path, a microscope objective lens disposed in the reflection-mode path, and a common-path interferometer comprising a diffraction grating, a Fourier lens, a pinhole, and a 2f system lens to collimate the reference beam and the imaging beam such that the collimated reference beam and imaging beam interfere with each other to form an interferogram at a final image plane.

Abstract: A system for producing an optical fiber with inscribed grating array is described. The system comprises a fiber drawing apparatus for drawing an optical fiber, a writing system for inscribing a grating in the optical fiber during the drawing process of the optical fiber and a controller for controlling the driving of the writing system. According to the present invention the fiber drawing apparatus also comprises a fiber length and/or drawing detecting means for determining the fiber length and/or fiber drawing speed and/or a fiber drawing parameter during the drawing process. The controller thereby is configured for capturing information from the fiber length and/or drawing detecting means and for controlling the writing system based on the captured information captured from the fiber length and/or drawing detecting means.

Abstract: 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.

Abstract: Described herein are techniques related to a semiconductor fabrication process that facilitates the enhancement of systemic conformities of patterns of the fabricated semiconductor wafer. A semiconductor wafer with maximized systemic conformities of patterns will maximize the electrical properties and/or functionality of the electronic devices formed as part of the fabricated semiconductor wafer. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: A device and method for detecting an angle of a shearer rocker arm based on optical fiber sensing. The device includes an optical system and a mechanical system. The optical system includes a broadband light source, a polarizer, collimating lenses, a gradient-rotation media plate, a polarization beam splitter, and a data processing module. The mechanical system includes a connecting base, connecting rods, a slider, a bracket, and a sensor housing. When the shearer operates, the rocker arm converts rotation angle information to linear displacement related to a gradient refractive index by using a connecting rod mechanism, and a position on the gradient-rotation media plate through which linearly polarized light produced by the optical system passes also changes. Due to an optical rotation effect, corresponding rotation angles of a plane of polarization that are formed after the light passing through the gradient-rotation media plate also vary.

Abstract: Example embodiments relate to methods and imaging systems for holographic imaging. One embodiment includes a method for holographic imaging of an object. The method includes driving a laser using a current which is below a threshold current of the laser. The method also includes illuminating the object using illumination light output by the laser. Further, the method includes detecting an interference pattern formed by object light, having interacted with the object, and reference light of the illumination light.

Abstract: A production system for measuring product thickness in tortilla and tortilla chip production includes a production line, including a cooker/grinder, a sheeter/cutter, and a conveyor belt; and a displacement measurement unit, including a processor, non-transitory memory, an input/output component, a laser sensor for measuring vertical displacement of the conveyor belt and objects thereon, a laser controller, and a displacement calculator. Also disclosed is a method for thickness measurement, including capturing samples, calculating a vertical displacement probability density function, and calculating average product thickness.

Abstract: A laser interferometer system includes a beam splitter to split a laser beam into first and second beam sets, a first retroreflector mounted to an object to reflect the first beam set, a first detecting device for detecting movements of the object in x-, y- and z-axis directions based on the reflected first beam set, a second retroreflector mounted to the object to reflect the second beam set, and a second detecting device for detecting rotations and movements of the object with respect to the y- and z-axis directions based on the reflected second beam set. The movements of the object in the z-axis direction obtained by the first and second detecting devices are used to obtain a rotation of the object with respect to the x-axis direction.

Abstract: The invention relates to a device for optical measurement of a thickness of an intransparent layer on a substrate, comprising first means for optical distance measurement configured to measure a first distance between a first reference plane and a first surface of the intransparent layer, and second means for optical distance measurement configured to measure a second distance between a second reference plane and a second surface of the intransparent layer. The second means measures a third distance between the second reference plane and a surface of the substrate. The thickness of the intransparent layer is computed from the first distance and the second distance. The measurement of the third distance is used to take into account the influence of the optical effect of the substrate on the distance measurement of the second distance. The invention also relates to a method for optical measurement of a thickness of an intransparent layer on a substrate.

Abstract: Encoder systems provide measurement and reference optical paths based on propagation in a common set of optical elements along paths that are displaced angularly or spatially. Associated measurement and reference beams are reflected by corner cubes to as to define first paths and second paths. The measurement and reference beams are combined to determine a work piece displacement in a manufacturing process.

Abstract: In various embodiments, a layer of organic encapsulant is provided over a surface of an ultraviolet (UV) light-emitting semiconductor die, and at least a portion of the encapsulant is exposed to UV light to convert at least some of said portion of the encapsulant into non-stoichiometric silica material. The non-stoichiometric silica material includes silicon, oxygen, and carbon, and a carbon content of the non-stoichiometric silica material is greater than 1 ppm and less than 40 atomic percent.

Abstract: A calibration system for calibrating a tilt angle of the fast steering mirror includes a position sensing device configured to generate a beam of electromagnetic radiation, and a diffractive optical element, positioned between the position sensing device and the fast steering mirror, the diffractive optical element being configured to divide the input beam into a plurality of output beams directed to the fast steering mirror. The position sensing device is configured to determine a tilt angle of the fast steering mirror. A method to calibrate a tilt angle of the fast steering mirror is further disclosed.

Abstract: Method include using an apparatus to measure a first surface field, at a first surface of the apparatus, of an artifact having one or more surface features with known topography. The method includes determining a first focus metric at the first surface based on at least a portion of a first surface profile containing the one or more surface features. Methods include digitally transforming, the first surface field into a second surface field at a second surface of the apparatus, deriving, a second surface profile from the second surface field and computing a second focus metric for the second surface profile, and determining, based on two or more focus metric values, an optimum surface for evaluating the instrument transfer function. Method include determining the instrument transfer function of the apparatus based on at least a portion of the surface profile derived from the surface field of the optimum surface.

Abstract: A film thickness measurement device 1A includes a light emission unit 10 for emitting light onto a measurement object 100, a light detection unit 20A for detecting the wavelength-dependent intensity of reflected light, and a film thickness calculation unit 30A for determining the film thickness of a first film 102 by comparing measured spectral reflectance obtained based on the detection result in the light detection unit 20A with theoretical spectral reflectance that takes into account front surface reflectance, front surface transmissivity, and back surface reflectance. The film thickness calculation unit 30A compares the measured spectral reflectance with a plurality of values of the theoretical spectral reflectance obtained by changing the front surface reflectance value, the front surface transmissivity value, and the back surface reflectance value, and determines the film thickness of the first film 102 based on the theoretical spectral reflectance closest to the measured spectral reflectance.

Abstract: In one aspect, the present disclosure provides a system for Fourier ptychographic microscopy, the system comprising (i) an image capture apparatus including an objective lens, (ii) at least one processor, and (iii) data storage including program instructions stored thereon that when executed by the at least one processor, cause the system to: (a) capture, via the image capture apparatus, a plurality of initial images of an object, wherein each of the plurality of initial images of the object have a first resolution, and (b) process each of the plurality of initial images in Fourier space to generate a final image of the object having a second resolution, wherein the second resolution is greater than the first resolution.

Abstract: An interferometer includes a light source, a beam splitter, a reference reflector, a measuring reflector, a detection unit, and at least two transparent plane-parallel plates. The beam splitter splits a beam of rays into at least one measuring beam and at least one reference beam. Until being recombined, the measuring beam propagates in a measuring arm, and the reference beam propagates in a reference arm. The reference beam falls at least three times on the reference reflector located in the reference arm. The measuring reflector is disposed in the measuring arm and is joined to an object to be measured, which is movable along a measuring direction relative to the reference reflector. The measuring beam falls at least three times on the measuring reflector. At least one distance signal with regard to the position of the object to be measured is ascertainable from the interfering measuring and reference beams via the detection unit.

Abstract: A phase sensitive detection mechanism that uses electrical processing is realized, and an optical detection device, an optical detection method, and a program that are capable of detecting faint light at high speed and with high sensitivity are provided by a simple configuration. A light source section generates a first pulsed light. A filter section transmits a second pulsed light formed from a portion of a frequency spectrum exhibited by the first pulsed light, and reflects a third pulsed light formed from another portion of the frequency spectrum exhibited by the first pulsed light. A phase modulation section phase modulates the second pulsed light at plural phases. A multiplexing section produces a fourth pulsed light by multiplexing the third pulsed light with the second pulsed light phase modulated by the phase modulation section. A detector spectrally disperses and detects scattered light generated by radiating the fourth pulsed light onto a target object.

Abstract: In a microparticle measurement device, a sample is passed through each channel in a multi-flow channel, and a predetermined linear area is illuminated with light. Measurement light originating from a microparticle in the sample, such as scattered or fluorescent light, is shaped into a parallel beam by an objective lens and passes through a first and second transmission portions. The beams transmitted through these two portions are converged as first and second measurement beams onto the same straight line by a cylindrical lens. The intensity of the interference light formed by these beams is detected with a detector. Meanwhile, the light emitted from the light source and passing through the multi-flow channel without hitting the microparticle falls through the objective lens onto a non-reflection portion and does not travel toward the cylindrical lens. Accordingly, only the interference light formed by the measurement beams is allowed to fall onto the detector.

Abstract: The invention provides an apparatus and method for scanning, imaging and treating the retina of an eye. The apparatus (10) comprises a source of collimated light (14), a two-dimensional scanning device (16) having two axes of rotation (16a, 16b), wherein the axes of rotation (16a, 16b) are orthogonal and substantially planar, and wherein the source of collimated light (14) and the two-dimensional scanning device (16) combine to provide a two-dimensional collimated light scan from a point source (22). The apparatus (10) further comprises a scan transfer device (18), wherein the scan transfer device (18) has two foci (18a, 18b) and the point source (22) is provided at a first focus point (18a) of the scan transfer device (18) and an eye (12) is accommodated at a second focus point (18b) of the scan transfer device (18), and wherein the scan transfer device (18) transfers the two-dimensional collimated light scan from the point source (22) into the eye (12).

Abstract: A scanning monochromatic spatial low-coherent interferometer (S-LCI) can be used to simultaneously measure geometric thickness and refractive index. The probe beam of the scanning S-LCI can be an off-axis converging single wavelength laser beam, and the decomposed incident angles of the beam on the sample can be accurately defined in the Fourier domain. The angle dependent phase shift of a plane parallel plate or other sample can be obtained in a single system measurement. From the angle dependent phase shift, the geometric thickness and refractive index of the sample can be simultaneously obtained. Additionally or alternatively, the S-LCI system can interrogate the sample to profile the location and refractive index of one or more layers within the sample using the disclosed techniques.

Abstract: A measurement apparatus including a housing having a first arm and a second arm spaced apart from the first arm to define a measurement zone therebetween, and a laser radar unit, wherein the laser radar unit emits a laser beam that is split into a first beam and a second beam, the first beam travels through the first arm, across the measurement zone and into the second arm, while the second beam travels through the second arm, across the measurement zone and into the first arm, thereby forming a closed optical path, and wherein the closed optical path includes a midpoint that is offset from the measurement zone such that the first beam travels a first optical path and the second beam travels a second, longer optical path when the closed optical path is broken by a part positioned in the measurement zone.

Abstract: Systems and methods of controlling a deposition rate during thin-film fabrication are provided. A system as provided may include a chamber, a material source contained within the chamber, an electrical component to activate the material source, a substrate holder to support the multilayer stack and at least one witness sample. The system may further include a measurement device and a computational unit. The material source provides a layer of material to the multilayer stack and to the witness sample at a deposition rate controlled at least partially by the electrical component and based on a correction value obtained in real-time by the computational unit. In some embodiments, the correction value is based on a measured value provided by the measurement device and a computed value provided by the computational unit according to a model.

Abstract: The system includes a dual interferometer sub-system including a first and second channel. The system includes an illumination source. The illumination source includes a first laser source disposed along a first input path and a second laser source disposed along a second input path. The illumination sources includes a combiner-splitter element optically coupled to an output of the first laser source and an output of the second laser source and is configured to combine light of a first wavelength from the first laser source and light of a second wavelength from the second laser source. The combiner-splitter element is further configured to split the combined light into a first channel and a second channel of the dual interferometer sub-system, where the first and second each receive a portion of the light of the first wavelength and the light of the second wavelength.

Abstract: Provided is a fifth step for obtaining a removal depth of a second electrode mixture layer (first opaque layer) corresponding to an integrated value from the integrated value of the value corresponding to the number of applying pulses integrated thus far, based on a correlation between the value corresponding to the number of applying pulses of pulse laser and the removal depth of the second electrode mixture layer grasped in advance, once it is determined that a white light applying target has changed from the second electrode mixture layer to a solid electrolyte layer (second opaque layer) and acquiring the removal depth as a thickness of the second electrode mixture layer.

Abstract: A holography imaging system includes a first laser, a second laser, a transmitter optical system, a receiver optical system, and a detector array. The first laser has a constant frequency, and the second laser has a non-constant frequency. The transmitter optical system can illuminate a target simultaneously using portions of the first and second laser signals. The receiver optical system can focus a returned light onto the detector array. A first and second illumination point sources can direct portions of the first and second laser signals onto the detector array. The first and second illumination point sources are located in-plane with a pupil of the receiver optical system. The system can detect simultaneously holograms formed on the detector array based on the returned light and the portions of the first and second laser signals directed by the first and second illumination point sources.

Abstract: An apparatus enabling abnormality detection of a sample. A first interference optical system scans the sample with first signal light from a first sample optical path, making the first signal light interfere with first reference light from a first reference optical path, to detect first interference light. Optical path length difference between the first sample optical path and first reference optical path is changed based on the detection. A change in the optical path length difference is determined. A second interference optical system scans the sample with second signal light from a second sample optical path, making the second signal light interfere with second reference light from a second reference optical path to detect second interference light. Tomographic information of the sample based on detection of the second interference light is determined. A refractive index profile of the sample is obtained based on the change amount information and tomographic information.

Abstract: A dilatometer for measuring metallic samples. The dilatometer includes a sample holder configured to receive and clamp a sample, an induction coil arranged on the sample, the induction coil configured to heat the sample, and a sensor for measuring the temperature of the sample.

Abstract: The invention relates to an optical measuring device for acquiring in situ a difference in distance between a support and an edge region of an object to be measured. The optical measuring device has a measuring head with dual beam guide which directs a first measuring beam towards the support and a second measuring beam towards the edge region of the object to be measured. Means are provided for acquiring and forming reflection spectra of the first measuring beam which is directed towards the support and the second measuring beam which is directed towards the edge region of the object to be measured. The measuring device has a multi-channel measuring apparatus with one spectrometer line. An evaluation unit for the reflection spectra for acquiring the stage height between the support and the edge region of the object works together with a spectrometer and a display unit.

Abstract: A scatterometer, configured to measure a property of a substrate, includes a radiation source which produces a radiation spot on a target formed on the surface of the substrate, the size of the radiation spot being smaller than the target in one direction along the target, the position of the radiation spot being moved along the surface in a series of discrete steps. A detector detects a spectrum of the radiation beam reflected from the target and produces measurement signals representative of the spectrum corresponding to each position of the radiation spot. A processor processes the measurement signals produced by the detector corresponding to each position of the radiation spot and derives a single value for the property.

Abstract: In a tool length measuring method measuring a length of a tool based on a movement amount of the tool from a predetermined position when the tool is moved from the predetermined position in a predetermined direction and interrupts a laser beam, the movement of the tool in a direction in which the tool approaches a main body of a laser device is stopped when a static signal indicating that the tool is interrupting the laser beam is detected.

Abstract: The present invention provides an inexpensive range image sensor and etc. A range image sensor comprises diffractive optical elements and on which are formed diffractive gratings that change a traveling direction of incident parallel light so that in a coordinate space defined by a xyz-axis, the incident parallel light is split into split beams, and angles formed by the x-axis and line segments determined by projected light spots formed by the split beams on a predetermined projection plane intersecting the z-axis become predetermined angles. Furthermore, the range image sensor is provided with a distance determining unit for determining distances to the projected light spots on the basis of the tilting with respect to the x-axis of the line segments determined by the projected light spots formed on the object by the split beams.

Abstract: Analysis and characterization of semiconductor and free-metal devices using a plurality of “live” and stored interference patterns or data detected to determine or generate two-dimensional or three-dimensional information of at least one internal stress or signal, or determining the effects thereof of internal or external stresses acting upon or within the electrical signals applied to a device under test or evaluation having exterior surfaces, interior structures, electronic features as well as determining the effects thereof of chemicals, bioelectric materials, or substances, placed adjacent to the surface of the devices under test.

Abstract: A shape determining device (X) splits the original light beam from a light source (Y) into two light beams, directs the light beams to the front and back surfaces of the object (1) to be determined, and performs optical heterodyne interference using the split light beams at the front and back surfaces of the object (1) to be determined. In the shape determining device (X), each of the split light beams is further split into a main light beam and a subordinate light beam, the subordinate light beam interferes with the main light beam at each of the front and back surfaces before and after the illumination of the object (1) to be determined, the signals after the interference are phase-detected, and the difference between the phases acquired by the phase detection is detected at each of the front and back surfaces of the object (1) to be determined.

Abstract: The invention relates to a system and to a corresponding method for optical coherence tomography having an interferometer (10) which has a beam splitter (13), a first reflector (11) and a reflector (12) the optical distance (I) of which from the beam splitter (13) is changeable by a speed (v), and a detector (30) for collecting light which is reflected by a specimen (1) to be examined. In order to reduce the times required for the most reliable possible recording of interference patterns, provision is made such that the intensity of the light (14 or 4) injected into the interferometer (10) or emitted by the interferometer (10) is modulated with a modulation frequency (fM) which is not equal to the Doppler frequency (fD), the Doppler frequency (fD) being given by twice the ratio of the speed (v) of the change of the optical distance (I) between the reflector (12) and the beam splitter (13) to the average wavelength (?0) of the injected light (14): fM?fD=2·v/?0.

Abstract: The disclosure relates to a detection device for imaging an object, that comprises: a laser cavity for transmitting an original light signal at an original wavelength towards the object in order to generate an evanescent wave at the surface of the object; a conversion means adapted for converting the evanescent wave into a progressive signal; a re-injection means adapted for injecting the progressive signal into the laser cavity in order to generate interference inside the laser cavity between the progressive signal and the original light signal; a detection means adapted for detecting the interference in order to determine the characteristics of the object; characterized in that the device includes a wavelength modification means adapted so that the wavelength of the progressive signal injected into the laser cavity is different from the original wavelength.

Abstract: A method for measuring a via bottom profile is disclosed for obtaining a profile of a bottom of a via in a front side of a substrate. In this method, an infrared (IR) light source is transmitted from the back of the substrate to the bottom of the via through an objective by using an IR-microscope, and lights scattered from the bottom of the via are acquired by an image capturing device to generate an image, where the image displays a diameter (2Ea) of the via bottom profile and a diameter (2Ec) of a maximum receivable base area of the via for the IR-microscope. Thereafter, by using an elliptic equation, a minor axis radius thereof (Eb) is obtained, and thus the via bottom profile is obtained from a radius (Ea) of the via bottom profile and the minor axis radius (Eb) of the elliptic equation.

Abstract: Phase differences associated with a defocused wavefront can be determined from a single color image. The color image, which is a measurement of intensity as a function of wavelength, is used to calculate the change in intensity with respect to wavelength over the image plane. The change in intensity can then be used to estimate a phase difference associated with the defocused wavefront using two-dimensional fast Fourier transform solvers. The phase difference can be used to infer information about objects in the path of the defocused wavefront. For example, it can be used to determine an object's shape, surface profile, or refractive index profile. It can also be used to calculate path length differences for actuating adaptive optical systems. Compared to other techniques, deriving phase from defocused color images is faster, simpler, and can be implemented using standard color filters.

Abstract: The present invention relates to a scanning microscope using a heterodyne interferometer, which can be used for mapping or imaging complex optical parameters such as physical structures and material properties of a sample under test. The heterodyne interferometer is designed to provide in- and quadrature-phase interference signal which can be used for extracting the phase and amplitude change induced on the probe beam. The phase and the amplitude of the probe beam, which is reflected from or transmitted through the sample, are modified by the physical structures and material properties of the sample. Therefore, by scanning the probe beam, local variations of the phase and amplitude can be mapped, and, thereby, three-dimensional microscopic physical structures and material properties can be imaged by processing the phase and amplitude values.

Abstract: A compound common-path interferometer including first and second measurement arms for measuring a test object is arranged so that a reference optic of the first measurement arm is disconnected from a remainder of the first measurement arm and a coupling between the reference optics of the first and second measurement arms forms a monolithic measurement cavity for maintaining reference surfaces of the reference optics at a fixed spacing and orientation. Separate supports are provided for the monolithic measurement cavity and the remainder of the first measurement arm.

Abstract: A method of measuring a thickness of a coating on a substrate material. A first pulse of monochromatic light having a predetermined first wavelength is emitted toward the coating and substrate material. A second pulse of monochromatic light having a predetermined second wavelength is emitted toward the coating and substrate material, the second wavelength being different than the first wavelength. A first elapsed time is measured from emission of the first pulse of light to reception of a reflection of the first pulse of light from a surface of the substrate material at an interface with the coating. A second elapsed time is measured from emission of the second pulse of light to reception of a reflection of the second pulse of light from an outer surface of the coating. A thickness of the coating is determined as a function of a difference between the first and second elapsed times.

Abstract: An apparatus and method for determining a depth of a region having a high aspect ratio that protrudes into a surface of a semiconductor wafer are provided. The apparatus comprises a multi-wavelength light source, a semiconductor wafer holder for holding a semiconductor wafer, a head for directing the light source onto the semiconductor wafer, a spectrometer for collecting light comprising multiple wavelengths reflected from the semiconductor wafer and analysis means for determining a depth of the region from an interference pattern of light reflected from the semiconductor wafer by performing Fourier domain optical coherence tomography.

Abstract: An optical system performs imaging in a transmissive and reflective mode. The system includes an optical interferometer that generates interference phenomena between optical waves to measure multiple distances, thicknesses, and indices of refraction of a sample. Measurements are made through a galvanometer that scans a pre-programmed angular arc. An excitation-emission device allows an electromagnetic excitation and emission to pass through an objective in optical communication with the sample. An electromagnetic detector receives the output of the optical interferometer and the excitation-emission device to render a magnified three dimensional image of the sample.

Abstract: The disclosure relates to a detection device for imaging an object, that comprises: a laser cavity for transmitting an original light signal at an original wavelength towards the object in order to generate an evanescent wave at the surface of the object; a conversion means adapted for converting the evanescent wave into a progressive signal; a re-injection means adapted for injecting the progressive signal into the laser cavity in order to generate interference inside the laser cavity between the progressive signal and the original light signal; a detection means adapted for detecting the interference in order to determine the characteristics of the object; characterised in that the device includes a wavelength modification means adapted so that the wavelength of the progressive signal injected into the laser cavity is different from the original wavelength.

Abstract: Methods and apparatus are provided employing rapid scanning continuous wave terahertz spectroscopy and imaging for the non-destructive evaluation of materials such as animal hides and natural cork, and explosive detection, concealed weapon detection, and drug detection. A system employing an aperiodic detector array and implementing phase modulation at 100 kHz significantly reduces the imaging time and enables interferometric images of a THz point source to be obtained at several frequencies between 0.3 and 0.95 THz.