3D direct laser writing of Petabyte Optical Disk

We report novel results for 3D recording of an optical disk with ultra-high density. Multilayer 5 nm nanomarks were experimentally obtained by using fluorescent photosensitive glass-ceramics and an optical head with λ=650 nm and NA=0.60. The distance between adjacent 5 nm nanomarks has been reduced to 10 nm. Ultra-high density optical data is recorded by focusing laser beam of a CW laser diode operating at low power (Pmax=10 mW).