Interlayer crosstalk reduction of a multilayer Blu-ray Disc using a grating in a three beam optical system.
In multilayer optical discs, light reflected by out-of-focus layers, which we call interlayer crosstalk, causes the tracking error signal to fluctuate, making the readout signal unstable. We previously proposed a novel method to use a grating along the optical axis in the return path of a pickup to suppress the fluctuation of a differential push-pull (DPP) signal. We develop a pickup and evaluate its performance to stabilize the DPP signal experimentally. DPP signal fluctuation is suppressed to one-third (6% to 2%), and also satisfactory readout jitters (about 8%) are obtained for a triple-layer Blu-ray Disc (BD), which demonstrate the validity of this method to reduce interlayer crosstalk of multilayer optical discs.
Ide
Tatsuro
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Central Research Laboratory, Hitachi, Ltd., 1-280 Higashi-Koigakubo, Kokubunji, Tokyo 185-8601, Japan. tatsuro.ide.ps@hitachi.com
Kimura
Shigeharu
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Tatsu
Eriko
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Kurokawa
Takahiro
T
Watanabe
Koichi
K
Anzai
Yumiko
Y
Shintani
Toshimichi
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