Demonstration of high-density three-dimensional storage in fused silica by femtosecond laser pulses

Three-dimensional optical recording of high contrast spherical bits (diameter<300 nm) at a density of 500 G/cm3 in fused silica using a Ti:sapphire femtosecond laser is demonstrated. Bits are optically read out using both a confocal and a phase-contrast scheme. The recording density for different materials and recording mechanisms are discussed.