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Proceedings Paper

Versatile optical system for static and dynamic thermo-magnetic recording using a scanning laser microscope
Author(s): Warwick W. Clegg; David F. L. Jenkins; Na Helian; James Windmill; Robert Windmill
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Paper Abstract

Scanning Laser Microscopes (SLM) have been used to characterise the magnetic domain properties of various magnetic and magneto-optical materials. The SLM in our laboratory has been designed to enable both static and dynamic read-write operations to be performed on stationary media. In a conventional (static) SLM, data bits are recorded thermo-magnetically by focusing a pulse of laser light onto the sample surface. If the laser beam has a Gaussian intensity distribution (TEM00) then so will the focused laser spot. The resultant temperature profile will largely mirror the intensity distribution of the focused spot, and in the region where the temperature is sufficiently high for switching to occur, in the presence of bias field, a circular data bit will be recorded. However, in a real magneto-optical drive the bits are written onto non-stationary media, and the resultant bit will be non-circular. A versatile optical system has been developed to facilitate both recording and imaging of data bits. To simulate the action of a Magneto-Optical drive, the laser is pulsed via an Acousto-Optic Modulator, whilst being scanned across the sample using a galvanometer mounted mirror, thus imitating a storage medium rotating above a MO head with high relative velocity between the beam and medium. Static recording is simply achieved by disabling the galvanometer scan mirror. Polar magneto-optic Kerr effect images are acquired using multiple-segment photo-detectors for diffraction-limited scanned spot detection, with either specimen scanning for highest resolution or beam scanning for near real-time image acquisition. Results will be presented to illustrate the systems capabilities.

Paper Details

Date Published: 10 December 2001
PDF: 7 pages
Proc. SPIE 4449, Optical Metrology Roadmap for the Semiconductor, Optical, and Data Storage Industries II, (10 December 2001); doi: 10.1117/12.450096
Show Author Affiliations
Warwick W. Clegg, Univ. of Plymouth (United Kingdom)
David F. L. Jenkins, Univ. of Plymouth (United Kingdom)
Na Helian, Univ. of Plymouth (United Kingdom)
James Windmill, Univ. of Plymouth (United Kingdom)
Robert Windmill, Univ. of Plymouth (United Kingdom)

Published in SPIE Proceedings Vol. 4449:
Optical Metrology Roadmap for the Semiconductor, Optical, and Data Storage Industries II
Angela Duparre; Bhanwar Singh, Editor(s)

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