Carrier-to-noise ratio improvement with pulsed-laser readout on magnetically induced superresolution by center aperture detection disks

Abstract

Magnetically induced superresolution hy center aperture detection (MSR-CAD) using pulsed and conventional dc schemes were applied to magneto-optical disks to quantitatively evaluate readout performances. By simulation and experiments, it was found that carrier-to-noise ratio (CNR) in the pulsed-laser readout was ahout 2.5 dB higher than that in the dc readout scheme at mark size of 0.45 pm or shorter. Therefore, pulsed readout is feasible to improve CNR and recording density in MSR-CAD disks. Index Terms-Carrierto noise ratio (CNR), magnetically induced super-resolution by center aperture detection (MSR-CAD), pulsed-laser readout. SiNx 30 nm DyFeCo 50 nm SiNx 2 n m ~-~~~ ~~ GdFeCo 50 nm SiNx 80 n m PC Substrate 1.2 rnm ~ ~~~ ~~ ~~ ~~~ Fig. 1. MSR-CAD disk structure.