Timothy S. Gardner
IBM
9 Papers
101 Citations
Timothy S. Gardner is an academic researcher from IBM. The author has contributed to research in topics: Optical disc & Signal. The author has an hindex of 7, co-authored 9 publications.
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Papers
Measurement of 1-μm diam beams
Abstract: Measurements of beams of ~1 μm in diameter are presented. Three approaches, one using a Ronchi ruling, the other two based on knife-edge scan techniques are compared experimentally. Effects of Ronchi ruling accuracy and nonconstant scan velocity are discussed. Included are results of theoretical studies on the effect of imperfect scanning edges and non-Gaussian beam profiles on measurement results.
24
Patent
Focus error detection using an equal path length lateral shearing interferometer
Timothy S. Gardner,Ronald P. Stahl,Syed T. Shafaat +2 more
- 06 Nov 1992
TL;DR: In this paper, an equal path length lateral shearing interferometer is proposed for focus detection in optical data storage devices, which consists of a beamsplitter and two abutting roof prisms.
21
Patent
Laser power control independent of beamsplitter transmissivity
Milton Russell Latta,Timothy S. Gardner +1 more
- 24 Aug 1992
TL;DR: In this article, an optoelectronic system for controlling laser drive current to produce a power level at the target independent of changes in the transmissivity of a beamsplitter positioned in the optical path between the laser source and the target is presented.
14
Patent
Relative position sensing calibration for optical storage device
Alan August Fennema,Timothy S. Gardner,Brian Gerard Goodman,Yoshihiro Hirasaka +3 more
- 12 Nov 1993
TL;DR: In this paper, a relative position error signal is calibrated in an optical storage device in which a tracking error signal (TES) varies as the light beam shifts its position through the objective lens.
12
Patent
Common mode rejection control in an optical disk drive
Anthony G. Dewey,Paul H. Francois,Timothy S. Gardner,Hideaki Iwasaki,Morovat Tayefeh +4 more
- 12 Nov 1993
TL;DR: In this paper, an optical drive provides an internal routine for automatically optimizing the common mode rejection ratio of the magneto-optic data output signal, which corrects for mismatches in both the optical elements and in the electronic data circuits.
10