Optics: measuring and testing – By polarized light examination – Of surface reflection
Patent
1995-09-01
1997-06-10
Rosenberger, Richard A.
Optics: measuring and testing
By polarized light examination
Of surface reflection
356382, G01B 1114
Patent
active
056381786
ABSTRACT:
An apparatus and method for measuring the space between a transparent member such as a disk, and reflective member such as a slider, by detecting a change of polarization of a reflected light beam. The apparatus includes a light source that emits a light beam. The light beam is circularly polarized and directed onto the disk and reflected off of the interface between the disk and the slider. The reflected light beam is split into four separately polarized beams by a beam splitter/polarizer assembly. The four light beams have varying intensities that are measured by photodetectors. Stokes parameters are computed from electrical signals that are generated by the photodetectors. The Stokes parameters correlate to the change in polarization of the reflected light beam. Ellipsometric parameters delta and psi are computed from the Stokes parameters. The thickness of the space and the complex index of refraction (n and K) of the slider are computed from the delta and psi parameters, typically by computing two separate sets of ellipsometric parameters at two different spacing thicknesses.
REFERENCES:
patent: 3847485 (1974-11-01), Zanoni
patent: 4015127 (1977-03-01), Sharkins
patent: 4306809 (1981-12-01), Azzam
patent: 4593368 (1986-06-01), Fridge et al.
patent: 4826321 (1989-05-01), Coates et al.
patent: 5130866 (1992-07-01), Klaassen et al.
patent: 5202860 (1993-04-01), Takashashi et al.
patent: 5218424 (1993-06-01), Somargren
patent: 5247493 (1993-09-01), Kime et al.
patent: 5280340 (1994-01-01), Lacey
patent: 5311287 (1994-05-01), Amer
patent: 5335066 (1994-08-01), Yamada et al.
patent: 5343293 (1994-08-01), Berger et al.
patent: 5557399 (1996-09-01), de Groot
Wallace et al "Flying Height Testing at Near Contact," Data Storage, Sep./Oct 1995, pp. 55-58.
"Division-of-Amplitude Photopolarimeer (DOAP) for the Simultaneous Measurement of all Four Stokes Parameters of Light", Optica Acta, vol. 29(5), 1982, pp. 491-494 (no month).
"Electric Fields Produced by the Progagation of Plane Coherent Electromagnetic Radiation in a Stratiated Medium", J. of Optical Society of America, vol. 58(3), Mar. 1968, pp. 380-390.
"Static Stokes Ellipsometer: General Analysis and Optimization", J. of Modern Optics, vol. 38(5), 1991, pp. 889-896 (no month).
Lacey Christopher A.
Womack Kenneth H.
Phase Metrics
Rosenberger Richard A.
LandOfFree
Imaging polarimeter detector for measurement of small spacings does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Imaging polarimeter detector for measurement of small spacings, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Imaging polarimeter detector for measurement of small spacings will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-769304