Authors: Toshifumi Ohkubo Majung Park Masakazu Hirata Manabu Oumi Kunio Nakajima Terunao Hirota
Publish Date: 2007/01/20
Volume: 13, Issue: 8-10, Pages: 1077-1084
Abstract
The nearfield principle combined with thinfilm gaslubricated slider bearing technology is thought to be one of the most promising breakthroughs to overcome the difficult optical diffraction limit or wavelength shortening limit which governs traditional optical recording performance In light of this we have demonstrated high linear density 150 nm pattern length and high speed 10 MHz readout signals using the combination of a tapered circular aperture and a planar lens mounted on a quartz slider flying above a metal patterned medium In order to further improve both the spatial resolution and signaltonoise ratio of this device it is essential to minimize the spacing and laser power throughput of an aperture Also investigated was the effectiveness of a noncircular aperture which has approximately triangular configuration in combination with polarized light in simultaneously improving spatial resolution and increasing signal output In this paper we confirmed the predicted effectiveness on more practical condition of both high speed and compactness of head construction using a submicrometer size noncircular aperture which was mounted on a 15mmlong miniaturized optical head slider flying above a ROM medium having sub100nmlong chromium patterns The influence of the electricfield direction of the incident light and aperture to medium spacing on the readout signal are carefully evaluated by flying the aperture at spacing down to less than 50 nmThe authors would like to thank Dr Koji Uozumi and Noriyuki Saito NHK Spring Ltd for their providing picoslider suspensions and technical advices Authors would like to thank Mr Tamotsu Kusumi Nikon Corp for their processing fine 70 nm lineandspace patterns on chromium layered media The authors also would like to thank Dr Hisashi Ito NTT Advance Technology Corp for their forming high quality carbon overcoat on patterned media The authors also would like to thank Dr Takanori Doi Toda Corporation for his helpful suggestions and careful treatment in forming lubricant layer on the patterned medium
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