Abstract: A light inspection system and method of the surface and inside of a sample. The system includes a light source generating a light beam to impinge on a sample; an imaging system obtaining an image of said sample and including a parabolic mirror with a hole to allow the passage of the light beam towards the sample, and the redirection of a scattered light component of the sample towards a light capturing unit comprising a bundle of bifurcated fibers; the bundle of fibers having a central fiber and external fibers, the central fiber receiving scattered light from the surface and the external fibers receiving scattered light from inside the sample; a measuring system measuring a power and/or a spectrum collected in the central and the external fibers.

Abstract: The present disclosure discloses a spectrometer arrangement including an entrance-slit group including a slit wheel and a slit mask for introducing radiation into and for limiting the optical field of the spectrometer arrangement, a first dispersive element for spectrally decomposing the radiation in a main dispersion direction, and a second dispersive element for spectrally decomposing the radiation in a transverse dispersion direction that forms an angle with the main dispersion direction to yield a two-dimensional spectrum. The slit wheel is mounted rotatably about an axis of rotation and has a falcate opening having a width that changes depending on the angle. The slit mask includes an opening that is longer than a largest width of the falcate opening such that radiation radiates through the falcate opening of the slit wheel and the opening of the slit mask. The present disclosure further includes a corresponding method and an optical component group.

Abstract: An optical emission spectrometer has an excitation device for a sample to be examined, a dispersive element for spectrally decomposing light emitted by an excited sample, a multiplicity of photodiodes, which are arranged such that different spectral components of the emitted, decomposed light are detectable with different photodiodes, and a multiplicity of electronic readout systems for the photodiodes. A respective electronic readout system has a charge storage assembly comprising a plurality of individual charge storage devices, wherein the charge storage devices are interconnectable in cascading fashion, with the result that charges flowing in from an associated photodiode successively fill the charge storage devices. The respective electronic readout system can be used to read the charges of the individual charge storage devices of the charge storage assembly and/or the charges of subsets of the charge storage devices of the charge storage assembly.

Abstract: The present disclosure relates to system, method and apparatus including a chemically impregnated media, a fixed, white broad spectrum LED source, a recording device having a digital imaging sensor and a microprocessor, is provided. The recording device captures real-time video images of color changes that occur on the chemically treated media during exposure to a gas specimen indicating a targeted substance is responding on the media. The continuous video images are transmitted to the microprocessor and evaluated with a proprietary algorithm loaded onto the microprocessor, which can efficiently determine gas concentration, as well as, individual species of target gas or gases landing on the specific chemically treated media. The captured video recording of the media color change provides a record of the events for later verification and evaluation of a particular gas detection event.

Abstract: A laser beam profiler unit for measuring an intensity distribution of a laser beam oscillated from a laser oscillator includes a magnifying optical system for magnifying a spot diameter of the laser beam oscillated from the laser oscillator and focused by a condensing lens, a first transmission prism for attenuating the laser beam, a second transmission prism for further attenuating a laser beam reflected by the first transmission prism, an image capturing element for detecting the laser beam reflected by the second transmission prism, and an analyzer for analyzing an intensity distribution of a spot of the laser beam from data of the laser beam detected by the image capturing element.

Abstract: The colorimetry apparatus includes a light source for emitting light to a surface of a detected object, a diffraction grating for spectrally separating, for each wavelength, the light emitted from the light source and reflected by the detected object, and a line sensor including multiple pixels, for receiving the light, which is spectrally separated by the diffraction grating, for the each wavelength by the multiple pixels. The light source and the line sensor are arranged on the common substrate.

Abstract: An amplitude monitoring system, a focusing and leveling apparatus and a defocus detection method. The method includes: adjusting amplitude of a scanning mirror to a theoretical amplitude value and recording corresponding theoretical output voltage values of a photodetector; adjusting the amplitude of the scanning mirror and sampling real-time amplitude values of the scanning mirror and real-time output voltage values of the photodetector to calculate compensated real-time demodulation results, and recording real-time defocus amounts of a wafer table; subsequent to stepwise displacement of the wafer table, establishing a database based on the compensated real-time demodulation results and the real-time defocus amounts of the wafer table; and in an actual measurement, sampling in real time an actual amplitude value of the scanning mirror and actual output voltage values of the photodetector to calculate a compensated real-time demodulation result and finding an actual defocus amount of the wafer table.

Abstract: Aspects of blending data detected by a monochromator over multiple wavelength ranges is described herein. In one embodiment, the monochromator includes a diffraction grating, a grating drive motor that rotates the diffraction grating to provide, by diffraction of broadband light, first dispersed wavelengths of light and second dispersed wavelengths of light, a detector that detects a first reflection from the first dispersed wavelengths of light and a second reflection from the second dispersed wavelengths of light, and processing circuitry that blends data values from the first reflection and data values from the second reflection together to provide a spectrum of combined data values. By blending data detected over multiple ranges, measurements of relatively high precision and quality can be provided over a wider spectral range.

Abstract: A multi-band spectrum division device is provided, comprising: a first parabolic reflection mirror, planar multi-mirrors, an optical grating and a second parabolic mirror. The first parabolic mirror is configured to reduce the divergent angle of incident optical beam, and to generate a collimated optical beam. The planar multi-mirrors are configured to adjust the incident angles of collimated beam on the grating surface. The grating is configured to disperse the incident signals with multi-wavelengths. The second parabolic mirror is configured to focus the multi-wavelength signals on its focal plane. Besides, each of the planar multi-mirrors has different location and angle in this device.

Abstract: Aspects of a monochromator are described herein. In one embodiment, the monochromator includes a light source that provides light, a diffraction grating including a first diffraction grating and a second diffraction grating, a grating drive motor that rotates the diffraction grating to provide dispersed wavelengths of light, a detector that detects a portion of the dispersed wavelengths of light, and processing circuitry that controls a grating drive motor to regulate an angular velocity of the grating based on an angular orientation of the diffraction grating. By using a diffraction grating having multiple, different dispersive surfaces, measurements of relatively high precision and quality may be taken throughout a wider spectral range. In another aspect, the processing circuitry controls a sample drive motor to vary an angle of incidence of the dispersed wavelengths of light onto a sample for evaluation.

Abstract: A monochromator has at least one optical grating which is rotatable in relation to incident light of a source of light, a drive unit to rotate the optical grating by a connected drive rod around a longitudinal axis, and a control unit to control the drive unit and thereby the rotation of the optical grating. The drive unit further has a first damping element with at least one electrical conductive surface, and a second damping element which provides at least one magnetic field having a magnetic axis which penetrates the electrical conductive surface. One of the first and second damping elements is fixed to the drive rod and is rotatable along with the drive rod around the longitudinal axis thereof in relation to the other one of the second or first damping element.

Abstract: Aspects of a tandem dispersive range monochromator and data knitting for the monochromator are described herein. In one embodiment, the monochromator includes a tandem diffraction grating, a grating drive motor that rotates the tandem diffraction grating to provide, by diffraction of broadband light, first dispersed wavelengths of light and second dispersed wavelengths of light, a detector that detects a first reflection from the first dispersed wavelengths of light and a second reflection from the second dispersed wavelengths of light, and processing circuitry that knits together data values from the first reflection and data values from the second reflection to provide a spectrum of combined data values. By using a tandem diffraction grating having different dispersive surfaces, measurements of relatively high precision and quality may be taken throughout a wider spectral range, and the measurements may be knitted together to provide a spectrum of combined data values.

Abstract: Systems and methods for measuring a target in a sample, the target being capable of generating an emitted light in response to an excitation light. In an example system, an excitation light source generates the excitation light along an excitation optical path. An attenuation filter arrangement selectively adds an attenuation filter to the excitation optical path. The attenuation filter attenuates the excitation light by a corresponding attenuation factor. The excitation light exits the attenuation filter arrangement along the excitation optical path to illuminate the sample. A light energy detector receives the emitted light generated in response to the excitation light, and outputs a measured signal level corresponding to an emitted light level. If the light energy detector indicates an overflow, signal measurement is repeated with attenuation filters of increasing attenuation factors until the measured signal level does not overflow.

Abstract: A hyperspectral imaging system and a method are described herein for providing a hyperspectral image of an area of a remote object. In one aspect, the hyperspectral imaging system includes a fore optic with optics for acquiring and projecting an image from a remote object, a scannable slit mechanism with a plurality of slits for receiving the projected image, where the projected image simultaneously illuminates two or more of the plurality of slits, a spectrometer for receiving and dispersing images passing through the two or more simultaneously-illuminated slits, and a two-dimensional image sensor for recording images received from the spectrometer, where the images received from different slits are recorded on different sets of detection elements of the two-dimensional image sensor.

Abstract: Some embodiments concern a method of isolating low amplitude signals in one or more electrical signals. The method can include: using a data acquisition device to acquire one or more electrical signals; using a first processor to compute one or more first parameters related to the one or more electrical signals; using the first processor to determine one or more first portions of the one or more electrical signal that comprise one or more transient signals; using the first processor to selectively mask the one or more first portions of the one or more electrical signals to create one or more output signals; and adjusting a gain of the data acquisition device based upon one or more second parameters of the one or more output signals. Other embodiments are disclosed.

Abstract: A surface measurement instrument for obtaining surface characteristic data of a sample surface is described. Relative movement between a reference surface and a sample support is caused to occur while a sensor senses light intensity at intervals along a scan path to provide a series of intensity values representing interference fringes produced by a region of a sample surface during said relative movement and from which series of intensity values surface characteristic data can be derived. The sample support is both translatable and tiltable in at least one direction perpendicular to a scan direction so that the sample support can be both tilted to cause the scan path to be normal to the sample surface region and translated to compensate for translation movement due to the tilting.

Abstract: The invention is a detection system that provides for background removal from a field of view (FOV) of spectra. A panoramic field of regard may be partitioned into a large number of FOV's. An FOV may include spectra including that of a target substance. Such detection may require removing the spectra other than that of the target. This may amount to removal of the background with an estimated background developed from spectra of one or more FOV's which may be similar to the background of the FOV with the target. An estimation of the background may be a sum of a number of FOV spectra where each spectrum is assigned a weight, the total amount of the weights being one.

Abstract: A method for characterizing samples having units, by monitoring fluctuating intensities of radiation emitted, scattered and/or reflected by said units in at least one measurement volume, the monitoring being performed by at least one detection means, said method comprising the steps of: a) measuring in a repetitive mode a number of photon counts per time interval of defined length, b) determining a function of the number of photon counts per said time interval, c) determining a function of specific brightness of said units on basis of said function or the number of photon counts.

Abstract: A detection system which provides for continuous background estimation removal from a sequence of spectra. A panoramic field of regard may be partitioned into a large number of fields of view (FOVs). An FOV may have a chemical vapor cloud. The small FOV may maximize detection of the cloud. Such detection may require removing the spectral characteristics other than that of the target cloud. This may amount to removal of background spectra with an estimated background developed from one or more FOVs which may or may not be similar to the background of the FOV with the target cloud. A number of estimated background spectra of the other FOVs may be used individually to greatly increase the detection probability of the target chemical.

Abstract: Provided is an optical device, comprising a plurality of polarizers that are arranged along a propagation direction of incident light; a first phase element that is disposed between the plurality of polarizers and that has a phase lag axis forming a prescribed angle relative to transmission axes of the polarizers arranged along the propagation direction; and a second phase element that is disposed between the first phase element and one of the polarizers arranged along the propagation direction, and that provides the incident light with a prescribed phase difference. An angle of the phase lag axis of the second phase element is adjusted such that the optical device transmits light in a prescribed wavelength region in the incident light.

Abstract: A swept wavelength interrogation system includes a tunable light source for outputting a light beam that is tunable over a range of wavelengths and an optical reader head for distributing the light beam among a plurality of sensors and for measuring response spectra from the sensors. A wavelength-tracking device measures centroid wavelengths of the light beam. A processor calculates a centroid wavelength of the response spectra from the sensors based on the measured centroid wavelengths of the light beam.

Abstract: A charge controlling circuit controls charging of a lithium-ion rechargeable battery. An electric power supplied from an external charger to the lithium-ion rechargeable battery is taken by a charging terminal. When the charging terminal is connected to the external charger, whether or not a charge prohibition condition is satisfied is determined by a CPU. A charging operation is prohibited when the charge prohibition condition is satisfied, but is permitted when the charge prohibition condition is not satisfied. Here, the charge prohibition condition includes a shortest time condition that a time during which the charging terminal is detached from the external charger is above a defined time decided in view of an instantaneous power interruption.

Abstract: A method of analyzing a dataset of spectra is provided in which each spectrum has a count value for each of a number of parameter values within a parameter range. The method is for identifying one or more parameter values that exhibit a significant variation within the dataset. A dataset of spectra is obtained and a statistical analysis is applied to the count values for each of the parameter values. The result of the analysis for each parameter value is a function of the variation in the count values. A spectrum that is representative of at least part of the dataset of spectra is then displayed together with the results of the statistical analysis. A corresponding computer program and system for performing the method are also disclosed.

Abstract: An optical spectrum analyzer includes an optical section 130 for executing light dispersion into a spectrum and wavelength sweep for input measured light, converting the measured light into an electric signal, and outputting the electric signal, a control section 101 for controlling the wavelength sweep of the optical section and outputting a sampling clock of a period shifting from a cycle period of the measured light for each wavelength of the wavelength sweep, and a measurement section 140 for executing sequential sampling of the electric signal from the optical section for each sampling clock.

Abstract: The development of a multiple-channel dual phase lock-in optical spectrometer (LIOS) is presented, which enables parallel phase-sensitive detection at the output of an optical spectrometer. The light intensity from a spectrally broad source is modulated at the reference frequency, and focused into a high-resolution imaging spectrometer. The height at which the light enters the spectrometer is controlled by an acousto-optic deflector, and the height information is preserved at the output focal plane. A two-dimensional InGaAs focal plane array collects light that has been dispersed in wavelength along the horizontal direction, and in time along the vertical direction. The data is demodulated using a high performance computer-based digital signal processor. This parallel approach greatly enhances (by more than 100×) the speed at which spectrally resolved lock-in data can be acquired.

Abstract: A sensor for measuring at least selected component in a composition can include: (a) a broadband light source, (b) an acousto-optic tunable filter (AOTF), (c) means for generating a beam of light from the light source and directing the beam of light at the AOTF wherein the AOTF is tuned to pass detection light having a desired wavelength range to detect the presence of the at least one component in the composition, (d) means for directing the detection light of known wavelength to the composition, (e) detection means for receiving light that emerges from the composition, and (f) a control signal generator configured to provide the AOTF with at least one desired wavelength range that is characteristic of the least one component in the composition. As an example, the sensor can be used to measure the thickness of optically transparent films.

Abstract: An optical spectrum analyzer is implemented with a detector combined with a tunable filter mounted on a stage capable of 360-degree rotation at a constant velocity. Because of the constant rate of angular change, different portions of the input spectrum are detected at each increment of time as a function of filter position, which can be easily measured with an encoder for synchronization purposes. The unidirectional motion of the mirror permits operation at very high speeds with great mechanical reliability. The same improvements may be obtained using a diffraction grating or a prism, in which case the detector or an intervening mirror may be rotated instead of the grating or prism.

Abstract: An optical spectrum analyzer (OSA) 10 sequentially or selectively samples (or filters) a spectral band(s) 11 of light from a broadband optical input signal 12 and measures predetermined optical parameters of the optical signal (e.g., spectral profile) of the input light 12. The OSA 10 is a free-space optical device that includes a collimator assembly 15, a diffraction grating 20 and a mirror 22. A launch pigtail emits into free space the input signal through the collimator assembly 15 and onto the diffraction grating 20, which separates or spreads spatially the collimated input light, and reflects the dispersed light onto the mirror 22. A ?/4 plate 26 is disposed between the mirror 22 and the diffraction grating 20. The mirror reflects the separated light back through the ?/4 plate 26 to the diffraction grating 20, which reflects the light back through the collimating lens 18. The lens 18 focuses spectral bands of light (?1–?N) at different focal points in space.

Abstract: An optical spectrum analyzer includes an optical section 130 for executing light dispersion into a spectrum and wavelength sweep for input measured light, converting the measured light into an electric signal, and outputting the electric signal, a control section 101 for controlling the wavelength sweep of the optical section and outputting a sampling clock of a period shifting from a cycle period of the measured light for each wavelength of the wavelength sweep, and a measurement section 140 for executing sequential sampling of the electric signal from the optical section for each sampling clock.

Abstract: A system for spectral analysis of a multi-wavelength signal is disclosed. The illustrative embodiment of the present invention, like the prior art, uses a grating or prism to disperse the spectral components of a multi-wavelength signal, and then uses a reciprocating or rotating mirror to direct the spectral components, one at a time, into a photodetector. The illustrative embodiment uses a telescope between the grating and the mirror to improve the spectral resolution of the system.

Abstract: The present invention is directed to method and apparatus for measuring the spectral characteristics of an object from a formed object generated input signal. The method comprises the steps of directing the input signal onto a diffraction grating. Diffracted signals are directed to a resonant mirror assembly for sequentially focusing a select diffracted signal. From that focused select diffracted signal, a spectral characteristic of said object is determined. Each said spectral characteristic is associated with each corresponding focused select diffracted signal and the associated signals are published. The apparatus is an improved spectrometer comprising a fiber cable assembly for receiving an object generated input signal and a diffraction grating. A resonant mirror assembly sequentially focuses a select diffracted signal, a sensor sensing which diffracted signal has been focused from the diffraction grating.

Abstract: A fluorescence detection apparatus irradiates a sample with an excitation light having different wavelengths, spectrally detects fluorescence from the sample, and includes: a comparison unit for comparing the wavelength of the excitation light with the starting wavelength of a fluorescent spectrum detection bandwidth; and a determination unit for determining an excitation light irradiation timing such that the irradiation of the excitation wavelength is stopped when the wavelength of the excitation light is longer than the starting wavelength.

Abstract: The present invention is directed to apparatus and method for measuring the spectral characteristics of an object surface. The apparatus comprises a light source for generating an input signal comprising a plurality of wavelengths of energy and a diffraction grating for diffracting the input signal into a plurality of diffracted wavelengths of energy. A resonant mirror assembly associated with the diffraction grating sequentially directs a select diffracted wavelength to the object surface to generate a corresponding reflected wavelength of energy. The apparatus further comprises a sensor for determining each select diffracted wavelength of energy directed to the object surface and a detector for detecting one or more of the reflected wavelengths. The detector is coupled with the sensor for associating each select diffracted wavelength with each corresponding reflected wavelength.

Abstract: A method for determining atomic isotope masses in mass spectrometry, atomic isotope ratios being determined from molecular isotope ratios measured by means of an isotope mass spectrometer—ion correction, the determination of the atomic ratios being carried out by setting up and solving a system of equations which describes relationships between the atomic and the molecular ratios, and the system of equations having to have at least as many independent equations as there are atomic ratios. The entire system of equations is linearized by means of suitable numerical methods in a first step, in particular by means of a Taylor expansion or similar method, and in which the linearized system of equations is subsequently solved as a whole without transforming the individual equations.

Abstract: The present invention is based on the knowledge that the advantages of a moveable dispersive element with regard to the simple detector element and the adjustability of the measurement range and the resolution can also be used in a miniaturization of a spectrometer, when the dispersive element is operated generally in resonance instead by a quasi-static drive. A proposed spectrometer comprises a vibratably suspended dispersive element for spectrally decomposing a light beam, whose spectral distribution is to be determined, into spectral components, a means for putting the vibratably suspended dispersive element into a vibration with a frequency, which is in such a ratio to the natural frequency of the vibratably suspended dispersive element that a resonance amplification of the voltage of the dispersive element occurs, and a detector for detecting a spectral component of the light beam.

Abstract: A method and apparatus for measuring characteristics of a single-wavelength optical signal constituting part of a wavelength division multiplexed (WDM) optical signal is provided. The WDM optical signal is adjustably diffracted to select the single-wavelength optical signal. An optical-to-electrical conversion is performed. An electrical sampling signal representing the selected single-wavelength optical signal is generated by one of (a) optically sampling the selected single-wavelength optical signal to generate an optical sampling signal on which the optical-to-electrical conversion is performed, and (b) electrically sampling an electrical signal generated by performing the optical-to-electrical conversion on the selected single-wavelength optical signal.

Abstract: A method for spectral analysis of the light proceeding from a specimen using a multi-band detector comprises the steps of defining an overall spectral region; from the overall spectral region, defining a first spectral subregion and defining at least a second spectral subregion; simultaneously detecting the light proceeding from the specimen in the first and the second spectral subregion, and generating detection values; displacing the first spectral subregion and displacing the second spectral subregion within the overall spectral region; and repeating steps c) and d) until the light has been detected over the entire overall spectral region.

Abstract: A wavelength variable light source emits a light whose wavelengths continuously change from a preset start wavelength up to a stop wavelength to a measuring object. A timing information output section generates timing information showing emission timings of lights emitted from the wavelength variable light source and having start and stop wavelengths and a plurality of wavelengths obtained by delimiting the wavelengths between the start and stop wavelengths in predetermined steps. A light receiving section receives the light output from the measuring object and outputs a signal showing a measured value of a received light. A plurality of amplifiers receive the signal output from the light receiving section and amplify the signal at each predetermined amplification factor.

Abstract: The present invention concerns an optical arrangement for selection and detection of the spectral region of a light beam (1) in a confocal scanning microscope, having a means (2) for spectral dispersion of the light beam (1), having means (3) for selecting a definable spectral region (4), and having a detection apparatus (5). The optical arrangement should be able to scan or detect multiple narrow-band spectral regions of a spectral region to be detected, in as uninterrupted a fashion as possible and in variably adjustable steps.

Abstract: A wavelength monitoring system for continuously monitoring the wavelengths of different optical channels transmitted through a wavelength division multiplexed (WDM) fiberoptic system. In one construction, an optical diffraction grating is used to disperse the light being monitored onto a rotating polygon having mirrors on the facets thereof, such that the rotating polygon reflects the light onto a detector located behind a slit. In a second construction, the light is projected onto a rotating, hollow transparent cylinder having a thin film filter deposited on a surface thereof, wherein the thin film filter comprises a Fabry-Perot structure which has a gap which varies as a function of its position on the rim of the cylinder, such that the varying gap allows for a varying transmission wavelength which varies as a function of angular position. A detector is positioned in the interior of the cylinder to detect light passing through the rotating thin film filter.

Abstract: A method for accurately measuring the reflectance of translucent objects by illuminating small areas of the object is disclosed. The method involves determining the lateral diffusion error by use of a predetermined set of calibration standards. The lateral diffusion error is added to the uncorrected reflectance to produce the corrected reflectance value. The method has widespread potential applications in the paper, printing, textile, coating, and food industries.

Abstract: An optical spectrum analyzer 100 and a wavelength variable light source 101 have each a sweep synchronization start function. A correction function of the rotation speed of a motor 106 for varying the angle of a diffraction grating in a spectroscope 104 so that extracted wavelength and output signal light wavelength match over a setup sweep wavelength range is found from the output signal light wavelength characteristic relative to the rotation angle of a spectral element 119 and the extracted wavelength of the spectroscope 104, and the rotation angle of motor 106 for driving the spectroscope 104 is varied for each setup wavelength in accordance with the correction function, then sweep is performed.

Abstract: A wavelength monitoring system for continuously monitoring the wavelengths of different optical channels transmitted through a wavelength division multiplexed (WDM) fiberoptic system. In one construction, an optical diffraction grating is used to disperse the light being monitored onto a rotating polygon having mirrors on the facets thereof, such that the rotating polygon reflects the light onto a detector located behind a slit. In a second construction, the light is projected onto a rotating, hollow transparent cylinder having a thin film filter deposited on a surface thereof, wherein the thin film filter comprises a Fabry-Perot structure which has a gap which varies as a function of its position on the rim of the cylinder, such that the varying gap allows for a varying transmission wavelength which varies as a function of angular position. A detector is positioned in the interior of the cylinder to detect light passing through the rotating thin film filter.

Abstract: A system and method for real time process control, using a linearly swept tunable laser, which allows high speed in-situ monitoring and control of wavelength-specific properties of optical components. The invention comprises scanning an optical component with a high speed, high linearity tunable laser, and detecting optical output from the component during the scanning. Preferably, the invention also includes adjusting or controlling the optical properties of the component during scanning, according to detected optical output from the component. The invention is embodied in a process control system comprising a high speed, high linearity, tunable operatively coupled to an optical component which in turn is operatively coupled to an optical detector. A system control processor is operatively coupled to the tunable laser and detector. A processing control unit is associated with the optical component and is operatively coupled to the system control processor.

Abstract: The invention provides a mechanism for oscillating the spectral grating of a monochromator. The mechanism couples the spectral grating of the monochromator to an oscillating spatial linkage mechanism which accepts a rotational input and converts it into an oscillatory motion. A monochromator according to the invention comprises an oscillating grating that is oscillated by such spacial linkage mechanism drive.

Abstract: The invention provides calibrated spectrometers in a multi-spectrometer system, where chemical mechanical polishing endpoint detection is an issue. In one aspect of the invention, a spectrometer is calibrated by selecting a filter slide having a predetermined light transmittance or reflectance variation with location (e.g. angular or linear displacement) on the slide. Light is incident on locations on the filter slide, and this incidence light is either transmitted or reflected. Transmitted or reflected light is received by a spectrometer, and the wavelength measured is compared with the known wavelength that corresponds to its location on the slide. The spectrometer is calibrated by normalizing the wavelength readings obtained at various locations on the slide with the known readings dictated by the reference slide. The spectrometers are also calibrated to a standard light source for intensity of light.

Abstract: In order to start sweeping an optical spectrum analyzer 1 and a wavelength tunable light source 14 on the same timing, a motor 6 for driving a spectroscope 4 in the optical spectrum analyzer 1 is controlled. To this end, a drive circuit 7 outputs a control signal to determine the timing where the motor 6 starts to rotate. A wavelength control circuit 19 in the wavelength tunable light source 14 controls the sweep of the wavelength of single-mode oscillation from a light source unit 20 and starts sweeping the light source unit 20 in response to a signal externally supplied to control the timing of sweep start. As a result, the sweep of the wavelength being measured with the optical spectrum analyzer 1 and that of the wavelength of single-mode oscillation from the wavelength tunable light source 14 are started on the same timing and high-speed sweep is achieved.

Abstract: A wavelength monitoring system for continuously monitoring the wavelengths of different optical channels transmitted through a wavelength division multiplexed (WDM) fiberoptic system. In one construction, an optical diffraction grating is used to disperse the light being monitored onto a rotating polygon having mirrors on the facets thereof, such that the rotating polygon reflects the light onto a detector located behind a slit. In a second construction, the light is projected onto a rotating, hollow transparent cylinder having a thin film filter deposited on a surface thereof, wherein the thin film filter comprises a Fabry-Perot structure which has a gap which varies as a function of its position on the rim of the cylinder, such that the varying gap allows for a varying transmission wavelength which varies as a function of angular position. A detector is positioned in the interior of the cylinder to detect light passing through the rotating thin film filter.

Abstract: The present invention concerns an optical arrangement for selection and detection of the spectral region of a light beam (1) in a confocal scanning microscope, having a means (2) for spectral dispersion of the light beam (1), having means (3) for selecting a definable spectral region (4), and having a detection apparatus (5). The optical arrangement should be able to scan or detect multiple narrow-band spectral regions of a spectral region to be detected, in as uninterrupted a fashion as possible and in variably adjustable steps.

Abstract: In a monochromator including a light dispersing element rotatable about an axis, a linear motor for rotating the light dispersing element around the axis, an encoder for generating a signal representing a rotational position of the light dispersing element, and a linear motor controller for detecting the rotational position of the light dispersing element based on the signal generated by the encoder, the inventive monochromator is characterized in that the signal generated by the encoder has a waveform including no flat portion. That is, the strength of the signal must change if the rotational position of the light dispersing element changes even slightly. Using a linear motor as a driving unit for the light dispersing element, the monochromator of the present invention can rotate the light dispersing element constantly with a stable speed even at high speed.