Abstract

Femto second laser direct writing (Fs LDW) technique is well known for its ability to fabricate 3D structures inside the bulk without damaging the surrounding regions [1]. Recent demonstration of data storage using fluorescence from silver aggregates produced by post-irradiated silver doped glass [2] suffers from multiple steps involved in glass preparation. In this paper, we demonstrate high density data storage in plastics that exploits the fluorescence emitted by nanoclusters induced by a femtosecond laser within the micron scale modified region. A 800 nm Ti: Sapphire laser system at 1 KHz repetition rate producing 40 fs pulses with an energy of 2.5 mJ was used to fabricate microstructures in Poly (methylmethacrylate) (PMMA). Fluorescent centers were fabricated 300 µm below the surface by focusing femtosecond pulses using a 40× (0.55 NA) microscope objective. A high-speed resonant laser scanning confocal microscope (LSCM) was used to record the emission from the laser modified region in the plastics.

© 2015 IEEE