Towards ultra high density multi-layer disk recording by two-photon absorption

摘要

A high NA objective lens (NA>1) with a long working distance (>100 um) used together with a multilayer volumetric optical media provides an important direction towards the realization of ultra high density multi-layer recording by two-photon absorption. A high NA objective lens decreases bit size, increases the volumetric density, and reduces the recording laser power requirements for a given recording speed. Static recording experiments have verified the recording potential performance of a high NA lens utilizing a commercially available Olympus~(~R) MplanApo 100X/1.4NA oil immersion objective lens with recording lasers. Based upon these results, 1.2TB capacity can be achieved in a 5.25" format disk of 80 μm of material thickness. Recording results at 1.4NA indicate ～ 10x reduction in peak recording power at 1Mb/s or recording data rate increase of 10 x to 10 Mb/s with similar peak powers used at 0.5NA recordings. In addition our simulation and static readout experiments show that a high NA objective lens collects more fluorescence from a smaller volume and compensates the loss of the readout fluorescence caused by the smaller recorded bit size.