Computation of effective groove depth in an optical disk with vector diffraction theory.

Area of Science:

• Optical data storage physics
• Diffraction theory and simulation

Background:

• Accurate modeling of optical disk surface topography is crucial for data retrieval.
• The physical groove depth may not directly correlate with the simulated optical response.

Purpose of the Study:

• To investigate the effective groove depth using vector diffraction simulations.
• To analyze the influence of groove parameters, coatings, and incident polarization on effective depth.
• To understand the impact of numerical aperture on effective depth variations.

Main Methods:

• Performed vector diffraction simulations for various disk configurations.
• Varied groove parameters, coating materials, and incident light polarization states.
• Analyzed effective groove depth in relation to physical depth and optical parameters.

Main Results:

• Effective groove depth deviates from physical depth when track pitch nears the light source wavelength.
• Significant differences in effective depth are observed between s- and p-polarized light.
• Effective depth is generally shallower than physical depth, particularly for deeper grooves.

Conclusions:

• The effective groove depth is a critical parameter influenced by optical conditions, not just physical dimensions.
• Ray-bending effects and polarization-dependent reflectivity play key roles in determining effective depth.
• Objective lens numerical aperture and polarization must be considered for accurate optical disk simulations.