Abstract: An imaging device includes a pixel, and a signal processor configured to randomly apply a first set of signals including a first driving signal applied to a first light source, and a first set of control signals applied to the pixel that adhere to a quasi-Gray code scheme to generate first through eighth correlation signals based on light output from the first light source according to the first driving signal and reflected from an object. The signal processor is configured to randomly apply a second set of signals including a second driving signal applied to the first light source, and a second set of control signals applied to the pixel that adhere to the quasi-Gray code scheme to generate ninth through sixteenth correlation signals based on light output from the first light source according to the second driving signal and reflected from the object.

Abstract: The present invention includes: a laser that can change the emission wavelength of light; a light-emitting fiber that emits light output from the laser onto a rotor; a concave surface that is provided in a recessed manner in the rotor and reflects the light emitted from the light-emitting fiber; a light-receiving fiber that receives the light reflected by the concave surface; a photodetector that detects the intensity of the light received by the light-receiving fiber; and a control device that controls the laser and performs optical measurement. The intensity is detected by the photodetector while changing the emission wavelength of the laser; the emission wavelength at which the intensity is largest is selected; and optical measurement is performed by detecting the intensity of light reflected by the concave surface by using light having an emission angle determined by the selected emission wavelength.

Abstract: A system is provided for measuring distance or displacement, comprising: first and second laser sources configured to provide first and second laser outputs; a beam combiner configured to receive and combine at least part of the first and second laser outputs into a combined laser output; a signal calibrator configured to receive at least part of the first laser output, the second laser output, or the combined laser output, and output a calibration signal; a plurality of optical paths, including a first optical path, a second optical path, the plurality of optical paths being configured to direct at least part of the combined beam onto an optical detector to produce an interference signal; and a signal processor configured to receive the interference signal and determine a pathlength difference between the first and second optical paths.

Abstract: An optical device for measuring a distance includes a prism, a beam splitter, a detector and a light source. The prism has a first light-incident surface and a plurality of first light-transmitting surfaces. The first light-incident surface is opposite to the first light-transmitting surfaces. The first light-transmitting surfaces intersect at a vertex. The beam splitter has a light-passing surface, a second light-incident surface and a second light-transmitting surface. The second light-incident surface faces the first light-transmitting surfaces. The light-passing surface is opposite to the second light-incident surface. The beam splitter includes a partially mirror surface facing the light-passing surface and the second light-incident surface. The light-passing surface faces a grating. The detector corresponds to the second light-transmitting surface. The light source emits a light beam to the first light-incident surface. An optical axis of the light beam passes through the vertex and the beam splitter.

Abstract: A system that may include a radiation source to generate a beam of coherent radiation; traveling lens optics to focus the beam so as to generate multiple spots on a surface of a sample and to scan the spots together over the surface; collection optics to collect the radiation scattered from the multiple spots and to focus the collected radiation so as to generate a pattern of interference fringes; and a detection unit to detect changes in the pattern of interference fringes.

Abstract: One illustrative method disclosed herein includes the steps of forming a masking layer that covers a P-type transistor and exposes at least a gate cap layer of an N-type transistor, performing a first etching process through the masking layer to remove a portion of the gate cap of the N-type transistor so as to thereby define a reduced thickness gate cap layer for the N-type transistor, removing the masking layer, and performing a common second etching process on the P-type transistor and the N-type transistor that removes a gate cap layer of the P-type transistor and the reduced thickness gate cap of the N-type transistor.

Abstract: The present invention relates to a magneto-optical ceramic material which is characterized by being configured of an oxide ceramic that is mainly composed of an oxide that is represented by formula (1): (TbxRe1-x)2O3 (wherein Re represents at least one element that is selected from among scandium, yttrium, lanthanum, europium, gadolinium, ytterbium, holmium and lutetium, and 0.4?x?1.0). The magneto-optical ceramic material is also characterized in that the difference between the refractive index at the grain boundary and the refractive index of the main phase of the oxide ceramic crystal at 25° C. is 0.004 or less. The present invention is capable of reliably providing a magneto-optical ceramic material for Faraday rotators of optical isolators and the like, said magneto-optical ceramic material having good polarization state and large extinction ratio, and enables size reduction of an optical isolator that is used for fiber laser for processing machines.

Abstract: A tester for measuring a pitch static attitude of a head stack assembly including a laser transmitter configured to transmit laser beams, and a laser receiver configured to receive the laser beams from the laser transmitter, wherein the laser transmitter and the laser receiver are configured to receive a head stack assembly between the laser transmitter and the laser receiver. The tester also includes a laser guide located between the laser transmitter and the laser receiver, and configured to block the laser beams from entering a gap in the head stack assembly and reaching the laser receiver.

Abstract: A device for detecting disk asperities. The device includes an optical glide head. The glide head is not required to physically contact a disk for detection of the disk asperities. The optical glide head includes a waveguide configured to transmit light onto the disk and receive reflected light from the disk.

Abstract: A method and system for determining a shape of a portion of an air-bearing surface (ABS) of a head residing on a slider are described. The ABS is configured to fly at a fly height from and with a velocity with respect to a disk during normal operating conditions. The method and system include driving at least one heater residing in the head while the slider is substantially at the normal operating conditions with respect to the disk and the fly height. The shape of the portion of the ABS changes in response to the heater(s) being driven. The method and system also include performing Doppler measurements on the slider while the heater is driven. The shape may then be determined based on the Doppler measurements.

Abstract: Correction factors for the ALR and PTR parameters of magnetic-head sliders are determined by calculating an effective reflectivity and a corresponding PCOR at each pixel of the air-bearing surface. The absolute value of reflectivity at each pixel of the AlTiC air-bearing surface is obtained from an empirical equation relating it to modulation. The ratio of Al2O3 and TiC in the AlTiC surface is then calculated at every pixel assuming a linear relationship between the absolute value of AlTiC reflectivity and the theoretical reflectivity of each constituent. The linear relationship is then also used to calculate the effective (complex) reflectivity for the AlTiC material from the relative concentrations of Al2O3 and TiC at each pixel.

Abstract: An apparatus for measuring a distance such as, for example, a fly height distance. An apparatus includes a slider having an air bearing surface and an optical condenser assembly spaced apart from the air bearing surface of the slider. The optical condenser assembly includes an optical cap and an optical substrate having a first surface and a second surface. The first surface is spaced apart from the optical cap and the second surface is spaced apart from the air bearing surface of the slider.

Abstract: In one embodiment and method of the present invention, an optical interference fly height (FH) test apparatus for measuring FH is disclosed, in accordance with an embodiment of the present invention, to include a slider, a transparent disk, means for directing a light beam directed between the slider and the disk, and means for iteratively measuring an estimated FH using at least two points of measurement on the slider when the slider is moved away from the disk at a pitch angle, wherein the estimated FH is computed as a function of the pitch angle and during each iteration, a previously-estimated FH is used to converge the estimated FH so that the estimated FH is within a predetermined range from the actual FH.

Abstract: A method for optical flying height measurement, and a flying height tester.

Abstract: An apparatus and a method for measuring very small separations between a transparent or semi-transparent first body and a second body is disclosed. A light source produces light that is split into two distinct paths. One path is directed through the first body at two locations, one where it reflects from the interface at the separation to be measured, and another where the second body does not affect the reflection. The second path is directed at a frequency shifter. The two paths are recombined and interferometric variations of intensity are detected. The difference in phase between the measurement and reference areas with the second body not present, is subtracted from the difference in phase between the measurement and reference areas with the second body present. The difference in differences yields the phase change that occurs when the second body is introduced. The separation is calculated based on this phase change.

Abstract: An apparatus and a method for measuring very small separations between a transparent or semi-transparent first body and a second body, wherein one or more light sources produce light that is split into two distinct paths. One path is directed through the first body at two locations, one where it reflects from the interface at the separation to be measured, and another where the second body does not affect the reflection. The second path is directed at a frequency shifter, which shifts the frequency of the light. The two paths are recombined and interfereometric variations of intensity, substantially at the frequency of the shifter, are detected. The difference in phase between the measurement and reference areas with the second body not present is subtracted from the difference in phase between the measurement and reference areas with the second body present. The difference in differences yields the phase change that occurs when the second body is introduced.

Abstract: Provided is an optical near-field recording and reproduction apparatus capable of adjusting the intensity of optical near-field and the amount of light bouncing off on the bottom of a slider around a scatterer and the surface of a medium and traveling back to a light source. A reflecting layer is formed above a structure for generating an optical near-field, and multiple beam interference is caused between the reflecting layer and the surface of the medium. The amount of returning above an optical near-field generator element is adjusted by adjusting the distance between the reflecting layer and the surface of the medium.

Abstract: A method for optical flying height measurement, and a flying height tester.

Abstract: An optical coupling apparatus for a dual column charged particle beam tool allowing both optical imaging of an area of an integrated circuit, as well as localized heating of the integrated circuit to form silicide. In one embodiment, optical paths from a whitelight source and a laser source are coupled together by way of first and second beam splitters so that a single optical port of the dual column tool may be utilized for both imaging and heating. In another embodiment, a single laser source is employed to provide both illumination for standard microscopy-type imaging, as well as localized heating. In a third embodiment, a single laser source provides heating along with localized illumination for confocal scanning microscopy-type imaging.

Abstract: Embodiments of the invention provide a method of testing/adjusting magnetic disk devices, in which the method allows the tests/adjustments to be conducted by solving problems due to the data sizes and characteristics of test/adjustment programs. After assembly of a magnetic disk device, setup of various parameters, magnetic disk defect registration, and other test/adjustment steps are executed. Execution of the test/adjustment programs does not require a special test apparatus since they are executed in the magnetic disk device to be tested. In addition, the test/adjustment programs are formed up of multiple phases, and each phase is sequentially executed. Adoption of this program structure keeps the tests/adjustments clear from restrictions due to the data sizes and characteristics of the test/adjustment programs.

Abstract: An optical test stand using a blue light source to perform both intensity-based and phase-based interferometry creating improved estimates of the flying height of a slider off of rotating disk surface, and the flying height estimate as a product of that process. A first method using an optical test stand to perform both intensity-based and phase-based interferometry to create improved estimates of the flying height of a slider off of rotating disk surface, and the flying height estimate as a product of that process. Optical test stand may further include a test disk with a glass substrate compatible with disk in a hard disk drive and/or a light source actuator for positioning the first light source.

Abstract: An optical test stand using a first glass substrate compatible with the glass substrate of a disk for a hard disk drive. A first method uses an optical test stand to perform both intensity-based and phase-based interferometry to create improved estimates of the flying height of a slider off of rotating disk surface, and the flying height estimate as a product of that process. Optical test stand may further include a first light source only in the blue spectrum and/or a light source actuator for positioning the first light source.

Abstract: A flying height tester used to measure the flying height of a head of a hard disk drive. The flying height tester includes a transparent substrate that has an index of refraction greater than 1.5. Utilizing a substrate with an index of refraction no greater than 1.5 improves the flying height sensitivity of the tester.

Abstract: A flying height tester includes a glass disc facing a magnetic head slider under test; an optical system for guiding light to the glass disc so that multiple reflections of light occur between the glass disc and the magnetic head slider; a light sensor receiving reflection light from the glass disc to output light intensity data; and a processor which calculates back the flying height based on an output function of the light sensor. The processor calibrates intensity gain data and intensity offset data of the output function using the data obtained in a pseudo-zero state of the flying height. This pseudo-zero state is obtained by applying an index matching liquid between a first-calibration magnetic head slider, having the same optical constants as the magnetic head slider under test, and the glass disc, the index matching liquid having a refractive index identical to the glass disc.

Abstract: A system and method are disclosed for calibrating a hard disc drive magnetic head flying height tester by a calibration standard, which includes a mock slider and mock disc, by optical interference techniques.

Abstract: A system and method are disclosed for calibrating a hard disc drive magnetic head flying height tester by a calibration standard, which includes a mock slider and mock disc, by optical interference techniques.

Abstract: A method for dynamically measuring the spatial position and orientation of a slider used in a magnetic disk drive operates by directing one or more beams of light through a microscope to an interface between the slider and the magnetic disk. The light beam reflected from the slider-disk interface is used to derive the spacing between the surface of the disk and the multiple points on the slider so that the spatial position of the slider can be determined. The number of measured points on the slider is at least equal to the number of degrees of freedom of the slider so that the spatial position of the slider can be fully determined.

Abstract: A test media in the form of a disk for use in an apparatus for performing interferometric measurement/testing of fly heights of read-write head sliders, the disk having a central opening for use with a spindle for rotation about a central axis, comprising: a disk-shaped substrate comprised of a light transmissive material and including a pair of opposed, smooth, major surfaces; an optical underlayer in contact with one major surface; and a wear-resistant, protective overcoat layer on the optical underlayer for improving the tribological properties of the media; wherein the thickness of the optical underlayer is selected for enhancing the sensitivity of testing by increasing the intensity of reflected light of pre-selected wavelength received by a detector for fly heights within a pre-selected fly height region-of-interest.

Abstract: A system and method are disclosed for calibrating a hard disc drive magnetic head flying height tester by a calibration standard, which includes a mock slider and mock disc, by optical interference techniques.

Abstract: A system and method are disclosed for calibrating a hard disc drive magnetic head flying height tester by a calibration standard, which includes a mock slider and

Abstract: A system and method for high speed and precision measurement of the distance between at least two near contact surfaces using heterodyne interferometry is disclosed. One of the surfaces is an optically transparent element and the other surface is a substantially non-transparent element. A laser source produces an output having two superimposed orthogonally polarized beams having S and P polarization, with a frequency difference between them. The polarized beams are split into measurement and reference beams without altering the characteristics of the polarized beams. The reference beams are caused to interfere, and a reference photo detector detects the reference beams and provides a reference signal. The measurement beam strikes the object of interest at an oblique angle after passing through a glass plate having a polarization coating on the bottom surface close to the object of interest.

Abstract: A method and apparatus for performing interferometric measurement/testing of flying heights of read-write head sliders utilizing an improved rotating disk, the disk having a central opening for use with a spindle for rotation about a central axis, the disk comprising: a substrate comprised of a light transmissive material and including a pair of opposed, smooth, major surfaces; and a wear-resistant, protective overcoat layer on one of the major surfaces for improving the tribological properties thereof; wherein the optical properties of the one surface of the disk are optimized for enhancing the sensitivity of the interferometric measurement/testing by increasing the intensity of reflected light received by a detector of the apparatus.

Abstract: A method and fly-height tester include a moving medium and a slider mount that holds a slider in proximity with the medium so that the slider flies relative to the medium. At least one light emitting diode generates a light that is directed by optics so that it reflects off the medium and the slider. The reflected light is directed by second optics to at least one detector, where each detector is capable of generating an electrical signal based on the amplitude of at least one wavelength of light in the reflected light. A distance calculator then determines the distance from the slider to the medium based on the at least one electrical signal.

Abstract: A method and apparatus is claimed for measuring the distance between a slider and a transparent disk with sub-nanometer resolution. The flying height is measured by applying ellipsometry. The measurement is done by: providing a sampling light beam with adjustable initial polarization state by phase modulation, and with variable incident angles relative to the air film and reflecting the sampling light off of the specimen at a detection site forming a reflected light beam that is then reflected at the detection site again and then guided to both detectors for detecting the intensity and phase change of the light beam to determine the gap's thickness as well as passing some light to a microscope used for observation of the detecting site on the specimen.

Abstract: A method and apparatus for measuring the flying height of a slider above a disk surface and in-situ monitoring the slider disk interface comprising the steps of: providing a beam of light; providing a slider disk interface comprising a disk having a substantially transparent substrate and a thin film layer, a slider for carrying a read/write element, the slider having a reflective surface; and an air bearing having a thickness d3 for supporting the slider above the disk; directing the beam of light to the slider disk interface through the disk, the thin film layer, the air bearing and then to the reflective surface of the slider; and measuring one of the intensity and phase information of the light reflected from the slider disk interface to provide an indication of the thickness d3 of the air bearing and/or of the thin film layer.

Abstract: An improved glide head has optical marks on the air bearing surface. The glide heads can be used for detecting defects on disc surfaces following an evaluation of the fly height as a function of disc rotation. The optical marks provide a position for focusing light used in the optical measurement of fly height. The optical marks have measurably different optical properties from the portions of the air bearing surface not covered by an optical mark. The differences in optical properties of the optical marks can be used to adjust the position of the optical system relative to the glide head to ensure that the light is focused on an optical mark.

Abstract: A method and apparatus for measuring the flying height of a slider above a disk surface and in-situ monitoring the slider disk interface comprising the steps of: providing a beam of light; providing a slider disk interface comprising a disk having a substantially transparent substrate and a thin film layer, a slider for carrying a read/write element, the slider having a reflective surface, and an air bearing having a thickness d3 for supporting the slider above the disk; directing the beam of light to the slider disk interface through the disk, the thin film layer, the air bearing and then to the reflective surface of the slider; and measuring one of the intensity and phase information of the light reflected from the slider disk interface to provide an indication of the thickness d3 of the air bearing and/or of the thin film layer.

Abstract: A method and fly-height tester include a moving medium and a slider mount that holds a slider in proximity with the medium so that the slider flies relative to the medium. At least one light emitting diode generates a light that is directed by optics so that it reflects off the medium and the slider. The reflected light is directed by second optics to at least one detector, where each detector is capable of generating an electrical signal based on the amplitude of at least one wavelength of light in the reflected light. A distance calculator then determines the distance from the slider to the medium based on the at least one electrical signal.

Abstract: Interference light occurring between a first laser light of a reference phase and a second laser light of a measuring phase is divided via a light divider into two interference light beams to be directed in two directions. One of the divided interference light beams is received by a polarizing light separator, which separates components of the first and second laser lights from the received interference light beam. First and second light detectors convert respective light energy of the separated components into corresponding electric signals. Adder adds together the converted electric signals. Third light detector converts light energy of the other divided interference light beam into an electric signal. Comparator compares the electric signal from the third light detector with the output of the adder as a reference value, to generate a detection output of a predetermined phase.

Abstract: The present invention is an endpoint detector and a method for quickly and accurately measuring the change in thickness of a wafer in chemical-mechanical polishing processes. The endpoint detector has a reference platform, a measuring face, and a distance measuring device. The reference platform is positioned proximate to the wafer carrier, and the reference platform and measuring device are positioned apart from one another by a known, constant distance. The measuring face is fixedly positioned with respect to the wafer carrier at a location that allows the measuring device to engage the measuring face when the wafer is positioned on the reference platform. Each time the measuring device engages the measuring surface, it measures the displacement of the measuring face with respect to the measuring device. The displacement of the measuring face is proportional to the change in thickness of the wafer between measurements.

Abstract: An apparatus that can measure a space between a first surface and a second surface such as the air bearing between a slider and a disk. The apparatus may include a light source that can reflect a light beam from the slider and the disk. By way of example, the light beam can be reflected off of an Al2O3 cap of a slider. A birefringent element such as a Savart plate may split the reflected light beam into an ordinary beam and an extraordinary beam. The ordinary and extraordinary beams may combine to form an interference pattern that is detected by a photodetector. A controller receives data from the photodetector. The apparatus may have a mechanism which can vary a phase between the ordinary and extraordinary beams so that the controller can calculate a phase value &phgr;. The controller then computes the space from the phase value &phgr;. The variation in phase between the beams may be created by tilting the birefringent element, or moving the reflected light beam directed into the birefringent element.

Abstract: An apparatus that can measure a space between a first surface and a second surface. The apparatus may include a light source that can reflect a light beam from the first and second surfaces. A birefringent element may split the reflected light beam into an ordinary beam and an extraordinary beam. The ordinary and extraordinary beams are detected by a photodetector. The apparatus may include a controller that is coupled to the photodetector and which can compute the space from a phase value that is determined from data collected when the mechanism varies the phase between the ordinary and extraordinary beams, and a ratio between a first modulation amplitude detected from light reflected from the first and second surfaces and a second modulation amplitude detected from light reflected from the first surface when the second surface is not adjacent to the first surface. The ratio can also be used to compute the reflectance and index of refraction of the second surface.

Abstract: A distance measurement apparatus for measuring distance to the target by measuring a time elapsed from the emission of pulsed light to the target until the receiving thereof. This apparatus comprising a light-emitting section, a light-receiving section, a delay circuit for delaying at least one of generation of the trigger signal with respect to a measurement start signal and the outputting of the measurement stop signal with respect to the reflected pulsed light and outputting thus delayed signal, a reference clock section, time measuring sections consisting of a start-side and stop-side fractional time signal measurement sections and a counter section, and a distance measurement section for determining, based thus measured items, the distance to the target according to the time from the emission of the pulsed light to the receiving thereof.

Abstract: The present invention is directed to a method and apparatus for detecting reflected pulses from multiple targets in a field of view such that range to each target can be detected with high resolution, even when the targets are located over a relatively wide measurement range. Exemplary embodiments of the present invention can provide real-time acquisition of ranging data, and can be implemented in a practical cost-effective manner suitable for reconfiguration.

Abstract: A device and method of electronically obtaining range or distances from the device to the target utilizing a central processing unit (CPU) in combination with a pulse repetition frequency generator, a plurality of photodetectors and a transistor to transistor clock counter, in a lightweight and portable configuration. The device obtains a plurality of samples, which enables the CPU to determine filter delay, range resolution and count deviations so as to accurately determine range or distance measurement to within plus or minus one centimeter.

Abstract: In a light-wave distance meter based on light pulses, a light pulse radiation device radiates light pulses emitted by a light source device to a target of measurement, a light reception device receives reflected light pulses from the target, a sampling device samples reception signals, a timing device applies a dither of a certain range to the light pulse emission timing and sampling timing, a cumulative memory device stores sampled signals at a certain interval cumulatively, and a computation device calculates the distance to the target. The distance meter is capable of measuring the position of received light pulses at a resolution higher than the sampling timing.

Abstract: An electronic vernier for a laser range finder enhances the resolution of the range finder to that of the vernier without increasing the frequency of the range clock. The range finder includes a range counter circuit for storing the total integer number of clock pulses produced by a range clock and counted by a range counter. The vernier includes a tapped delay line which subdivides the clock pulses into a predetermined plurality of equal increments. The contents of the tapped delay line at the time of transmission of the ranging pulse, and reception of the reflected ranging pulse identify the phase of the clock pulse. An electronic storage register of the vernier captures and stores the contents of the tapped delay line, and then transfers vernier transmission and reception fractions to a system controller for computing a corrected range measurement from the total integer number of clock pulses produced by the range clock and counted by the range counter.

Abstract: An apparatus for measuring the transit time of electromagnetic waves operates with pulse frequencies (9, 10), conducted in a feedback loop (12) which are supplied after passing through a measurement path (13) or through a reference path (14) to a resonator (35). As a result of an 180.degree. phase-shift of the last pulse (10) of each pulse sequence (9, 10) the resonator oscillation collapses abruptly at a specific point in time. The directly preceding zero passage of the resonator oscillation defines the time of reception of the pulse sequence.

Abstract: A laser speed detector is described which includes a laser rangefinder which determines the time-of-flight of an infrared laser pulse to a target and a microprocessor-based microcontroller. The device is small enough to be easily hand-held, and includes a trigger and a sighting scope for a user to visually select a target and to trigger operation of the device upon the selected target. The laser rangefinder includes self-calibrating interpolation circuitry, a digital logic-operated gate for reflected laser pulses in which both the "opening" and the "closing" of the gate can be selectably set by the microcontroller, and dual collimation of the outgoing laser pulse such that a minor portion of the outgoing laser pulse is sent to means for producing a timing reference signal.