Effects of refractive-index mismatch on three-dimensional optical data-storage density in a two-photon bleaching polymer

Abstract

Reported is an investigation into the effect of spherical aberration caused by the mismatch of the refractive indices between the recording material and its immersion medium on the three-dimensional optical data-storage density in a two-photon bleaching polymer. It is found both theoretically and experimentally that spherical aberration can be compensated for by a change in the tube length at which a microscope objective is operated in recording and reading processes. After compensation for the spherical aberration it is possible to achieve a three-dimensional recording density of 3.5 Tbits/cm(3) for a commercial objective with a numerical aperture of 1.4.