This paper introduces the concept of producing a low cost, single layer ROM that is compatible with magnetic amplifying magneto-optical system (MAMMOS) technology.
We present a magneto-optical recording head designed for a 400 nm laser with a 0.85 numerical aperture doublet objective lens and a thin film Magnetic Field Modulation coil integrated in a flying slider.
Magneto-Optical (MO) disk possesses a very high advantage of high density recording compared to non magnetic optical disk, because MO recording is almost same as a perpendicular magnetic recording However, the high density recording is recorded by very tiny domains, so the readout MO signal decreases and the correct data reproduction becomes impossible. In order to amplify the small MO signal, one new idea has been proposed.
The read-out signal patterns by MAMMOS were classified and suitable read-out parameter (laser power, magnetic field) was estimated. By adjusting these parameters, both 0.2 micrometer size packed domain and modulated domains (T equals 0.2 micrometer) could be reproduced. The MAMMOS read-out from variously lengthened domains and eye pattern were obtained by application of a magnetic field synchronized with clock marks embossed on the disk.
A readout method to amplify the MO signal by using a magnetic domain expansion phenomenon have been proposed. It was found that the small MO signal reproduced from 0.08 micrometers crescent shaped domain was amplified 5 times larger than that of conventional disk without readout field. Also the reproduced signal level reaches to about 70% of the saturated signal amplitude. The result corresponds to 20 Gbit/in2 areal density with conventional 680 nm laser.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.