Microchannel fabrication in silica glass by femtosecond laser pulses with different central wavelengths

A newly developed tunable visible femtosecond laser source was used to fabricate microchannels in silica glass. For comparison, femtosecond laser pulses from a Ti-sapphire laser at 800 nm as well as from a femtosecond optical parametric amplifier at 1.3 µm were also employed to fabricate microchannels. We found that it is much more efficient to drill micro-channels using the visible pulses because of their lower damage threshold. The quality of the cross section of the microchannel is also better with this visible femtosecond laser source because of the high beam quality of the visible pulses.