Yusuke Kanatake

Write Strategy Optimization Method with Two-Step Search for Blu-ray Disc Recording

A new write strategy (WS) optimization method with a two-step search process for Blu-ray Disc (BD) recording is developed to shorten the optimization time. This method is realized by the WS optimization system, which is constructed with an optical pickup, a disc tester, and the WS optimization algorithm. The optimization is executed according to the two-step search process along the mathematical axis, which is experimentally derived from the sample WS parameters. As the experimental result, the optimization time is reduced by nearly two-thirds from that achieved using the conventional method performed by the experts. All the jitter values of the playback signal derived from the recorded marks are smaller than the 7% target value and the effectiveness of this new method is experimentally confirmed.

Fast adjustment method of spherical aberration and focus offset by elliptic equation

Fast adjustment method of spherical aberration and focus offset by elliptic equation was developed. In the case of Blu-ray disc™, spherical aberration is increased because of high NA optical system. In this paper, we introduce our new adjustment method of spherical aberration and focus offset and experimental result of the effectiveness of this method.