Femtosecond laser-assisted three-dimensional microfabrication in silica

We demonstrate direct three-dimensional (3-D) microfabrication inside a vol ume of silica glass. The whole fabrication process was carried out in two s teps: (i) writing of the preprogrammed 3-D pattern inside silica glass by f ocused femtosecond (fs) laser pulses and (ii) etching of the written struct ure in a 5% aqueous solution of HF acid. This technique allows fabrication of 3-D channels as small as 10 mum in diameter inside the volume with any a ngle of interconnection and a high aspect ratio (10-mum-diameter channels i n a 100-mum-thick silica slab). (C) 2001 Optical Society of America.