LOCAL MICROMODIFICATION OF NANOPOROUS GLASS BY FEMTOSECOND LASER BEAM
Microdomains manifesting polarization-sensitive birefringence were fabricated in nanoporous glass under the exposure to femtosecond laser pulses. It was shown by means of scanning electron microscopy that these microdomains are cavities with elliptical cross-sections surrounded with non-porous glass. It was revealed that an increase of a number of writing pulses leads to the elongation of the cavity along the axis perpendicular to the polarization plane of laser beam. Proof-of-concept of optical data storage with 3-bit multilevel encoding based on birefringence microcavities is demonstrated.