Optical design in high density and high capacity multi-layer data storage system

Fundamental requirements for optical system design for volume recording system is identified. Anastigmatic objective lens design is required for conventional page-based system, whereas for multi-layer volume recording systems, an Aplanatic and zoom optical design is needed with an afocal sub-optical system including a high numerical aperture (NA) objective element. An NA 0.4 and four element design is feasible by only using off-the-shelf components. Recording depth ranges of 0.4 mm for wavelength 532 nm and 0.2 mm for 405 nm. The design demonstrates sufficiently small as-built wavefront error, less than 0.1 waves while implementing focusing and tracking capabilities to the design.