Voxel-like modification of PMMA by combined effect of femtosecond Ti:sapphire laser fundamental frequency and second harmonic radiation

Summary form only given. Femtosecond lasers show outstanding capabilities for micromachining in a wide range of materials including transparent dielectrics. In particular, Glezer et al. (1996) demonstrated 3-D optical storage with a density exceeding 10/sup 10/ bits/cm/sup 3/ in glasses using femtosecond pulses. Currently, the femtosecond micromachining uses laser systems with chirped-pulse amplification technique. These lasers are complicated and difficult to operate and maintain. Another approach is development of micromachining methods using lower power laser sources. We have recently demonstrated micrometer-sized structural modification of doped polymers by a femtosecond laser without amplifiers. In the report we demonstrate an efficient, controllable production of voxel-like modifications in pure PMMA by simultaneous use of moderate power trains of femtosecond pulses at 385 and 770 nm wavelength.