Femtosecond laser induced photoluminescence in poly(methyl methacrylate) and three-dimensional optical storage

Abstract

We report on a femtosecond-laser induced photoluminescence (PL) in poly(methyl methacrylate) and its potential application to three-dimensional optical storage Irradiation with a focused 800 nm 1 kHz 100 fs pulsed laser induced a strong PL change in UV-visible region Absorption spectra and Fourier-transform Infrared spectra before and after laser irradiation indicate the PL may result from the emissive oxidized products of photo-degradation reaction of PMMA This makes it possible to read out the stored data by detecting the PL change The pulse energy threshold of the light-induced PL change of PMMA is found to be at similar to 2 mu J/pulse and the optimal recording energy is similar to 3 mu J/pulse A ten-layer pattern inside the bulk sample recorded by tightly focusing a pulsed laser beam was read out by a reflection-type fluorescent confocal microscope which detected the emission in visible range as the signal High-contract fluorescent images with a much higher signal-to-noise ratio were obtained without crosstalk in comparison with the ordinary reflection mode (C) 2010 Elsevier B V All rights reserved