VECTOR DIFFRACTION MODELING - POLARIZATION DEPENDENCE OF OPTICAL READOUT SERVO SIGNALS

Analytic formulae are derived for the incident polarization dependence of a light field reflected from an optical disk with embossed pits and grooves, on the basis of a vector diffraction theory using the mode expansion technique. The proposed formulation is applied to a bi-periodic structure suitable as a basis for discussion of the tracking servo and readout signals' dependence on incident polarization and disk geometry. Numerical results are also given and compared both with the results obtained by using a scalar diffraction model and with experimental data. Theoretical results on the polarization and depth dependence of servo-related signals agree fairly well with experimental data.