Crosstalk-Suppressed Readout System Using Shading Band

A readout system that uses a shading band to suppress crosstalk was developed. In this system, a shading band is placed in the collection path to shade the center part of the reflected beam along the track direction at the aperture plane. Crosstalk could be sufficiently suppressed when the width of the shading band was chosen so the readout signals that are obtained by detecting the resulting beam after this shading band are free from data patterns on adjacent tracks. Computer simulation results show that this method can suppress crosstalk in each track pitch by choosing suitable widths for both the recorded mark and the shading band. Experiments using a magneto-optical readout system that has a shading band in the collection path were performed to demonstrate the crosstalk suppression effects of this method. These results show that this method can reduce crosstalk by about 19 dB compared with conventional methods.