非点隔差を補正した光磁気ヘッド

抄録

This paper presents a magneto-optical head that corrects for astigmatism by rotating an inclinated transparent plate glass between a laser and collimating lens. Through astigmatism-correction, the best focus offset point for reproducing the carrier-to-noise ratio (CNR) coincided with the best point of tracking error (TE) signal level. For designing the inclinated glass plate, the thickness and the inclination angle were optimized in terms of wavefront aberration. A recording density of 0.34μm/bit was confirmed with a numerical aperture of(NA)=0.55 and 680 nm-laser in good condition of focus offset for both TE signal level and CNR.