title: Interlayer crosstalk reduction of a multilayer Blu-ray Disc using a grating in a three beam optical system.
abstract: 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.
authors.affiliation: Central Research Laboratory, Hitachi, Ltd., 1-280 Higashi-Koigakubo, Kokubunji, Tokyo 185-8601, Japan. tatsuro.ide.ps@hitachi.com
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Ide
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Kimura
authors.forename: Eriko
authors.initials: E
authors.lastname: Tatsu
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kurokawa
authors.forename: Koichi
authors.initials: K
authors.lastname: Watanabe
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Anzai
authors.forename: Toshimichi
authors.initials: T
authors.lastname: Shintani