Microstructuring transparent materials by use of nondiffracting ultrashort pulse beams generated by diffractive optics

We propose a method for microstructuring transparent materials by use of nondiffracting ultrashort pulse beams. Bulk glass arranged behind a diffractive axicon that creates a zero-order Bessel beam can be modified without being scanned in the depth direction. The whole region to be modified is irradiated by a spatially extended pulse beam; thus points at deeper depths are modified but are not affected by points at shallower depths. Not only the relationship of sample location to beam intensity field but also the pulse duration significantly influences bulk modification results. We have proved the effectiveness of method in forming microholes by applying it in silica substrates. (C) 2003 Optical Society of America.