Femtosecond laser micromachining on backside of glass using simultaneously spatially and temporally focused vortex beams

Femtosecond laser micromachining on back surface have been investigated experimentally using simultaneously spatially and temporally focused (SSTF) vortex beams. Uniform ring-shape ablations have been made on back surface of borosilicate glass. The feasibility of laser micromachining using femtosecond SSTF vortex beam has been demonstrated.