An efficient method and apparatus for taking the data needed for a glide test; the data includes measuring flying height of a slider over a regular rotating disk and measuring piezoelectric contact with the disk. An optical system provides a beam of light. To measure the flying height, part of the beam of light is reflected from a surface of the transparent slider. Another portion of the beam is reflected from the surface of a rotating disk. The two beams are transferred through an optical syste...

Interferometer 14 is equipped with a beam directing mechanism portion for causing the incoming laser beam to be reflected in the x, y, and z axis directions and a switching mechanism for the beam directing mechanism portion. Computer 20 provides driving commands sequentially to NC controller 22 in accordance with the contents of a measurement program to thereby operate milling machine A in accordance with a prescribed procedure, calculates correction data by comparing the distance measurement da...

A copy media registration module for positioning paper in a feed path is disclosed. More specifically, the present invention is directed to a method and apparatus for detecting pre-drilled holes in copy media. A sensor detects the presence and absence of copy media in the feed path. Once a transition from paper to no-paper, or from no-paper to paper occurs, subsequent signals from the sensor are ignored for a designated period of time. At the leading edge of the sheet, this designated time perio...

The present invention relates to a device for determining the shape of the wave surface transmitted by a substantially parallel-faced transparent component (P), which includes a support (S) for the component (P), an interferometer (I), means for moving the support (S), and a control unit which determines, from the measurements by the interferometer (I), the shape of said wave surface. According to the invention, the support (S) is made in such a way as to let the light beam (FM) emitted by the i...

A method of controlling a short-etalon Fabry-Perot interferometer used in an NDIR measurement apparatus includes generating a measurement signal using a radiant source. The measurement signal is provided to a sample point containing a gas mixture to be measured. The measurement signal is bandpass-filtered with an electrically tuneable Fabry-Perot interferometer using at least two wavelengths of the interferometer passband. The measurement signal is passed via an optical filter component prior to...

A displacement measuring method for measuring displacement of an object to be examined is disclosed, wherein light which contains two components having a small difference in frequency is separated into a first light of a firs wavelength and a second light of a second wavelength, having different frequencies. First light beam of the first light and a second light beam of the second light interfere with each other, wherein at least one of the first and second light beams is directed via the object...

A region of interest in a living body is exposed to excitation light, which causes it to produce fluorescence. The fluorescence is separated with respect to desired wavelength ranges and detected. A first detector detects an entire fluorescence component or a fluorescence sum component, which is the sum of a fluorescence component of a comparatively short wavelength region and a fluorescence component of a comparatively long wavelength region. A second detector detects a fluorescence component o...

A non-contact optical method and apparatus for use in inspecting and measuring defects on a disk. The apparatus generates an interference pattern from a reference beam reflected from a surface of a transparent slider with a second beam reflected from a surface of a test disk. The resulting interference pattern is processed by a set of photodetectors and processing electronics to quantify and map the location and magnitude of asperities on the disk.

An interferometer comprises a source of radiation (10) and a beam splitter (12) for forming two beams. The beams travel along different optical paths and the optical path difference of the paths can be varies by rotatable mirror pairs M2/M3 and M4/M5. One of the paths includes an adjustable mirror M6 which is tiltable in orthogonal directions. A control unit (18) can be automatically initiate periodically an alignment procedure for aligning the interferometer.

A variable chirp electro-optic modulator is provided that uses a single modulation signal. The modulator has several optical paths in the proximity of one or more modulation electrodes which are driven equally by a single modulation source. The amount of chirp desired of the modulator is controlled by varying the optical amplitude or phase of the light in the different paths.