| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide techniques for controlling the reading of micro-holograms from a holographic disk based on a target data layer to be read in the disk. <P>SOLUTION: Reading a target data layer which is relatively deep in the disk (e.g., farther from an optical head emitting a reading beam) involves using a higher power reading beam to compensate for power attenuation of a returned reading beam. For example, a power adjustment module is used to dynamically adjust a reading laser emitting the reading beam, based on the dynamically changing target data layer. By compensating for power attenuation in deeper target data layers, the variance of power in the returned reading beams is decreased, possibly improving the bit error rate in micro-hologram reading techniques. <P>COPYRIGHT: (C)2012,JPO&INPIT |
