Progressive Differential Push-Pull Method For Dual Layer Blu-ray Disc Recording

Progressive Differential Push-Pull (DPP) method was developed. In case of dual layer Blu-ray disc recording, conventional DPP signal is disturbed by the stray lights reflected from other recording layer and tracking servo sometimes becomes unstable. This paper presents an example of optical head for dual layer Blu-ray Disc recording. Photo detector of the optical head to suppress the influence of stray lights was developed.