Microchannel fabrication in PMMA based on localized heating by nanojoule high repetitions rate femtosecond pulses

Microchannels are fabricated in a poly(methyl methacrylate) substrate by high repetition rate, nanojoule femtosecond laser pulses. The mechanism for channel fabrication is based on the localized heating of the substrate due to the high repetition rate of the laser, resulting in smooth walled cylindrical channels. Microchannels with diameters of 8 – 20 µm can be fabricated at 800 µm/s using 80 fs pulses at a repetition rate of 80 MHz and energy of 0.9 nJ/pulse.