Holographic writing of volume-type microgratings in silica glass by a single chirped laser pulse

Refractive-index-modulated volume-type gratings were holographically encoded inside pure SiO2 glass plates by a single chirped (0.5-5 ps duration) laser pulse generated from a mode-locked Ti:sapphire laser (wavelength similar to800 nm, emission pulse duration similar to100 fs). Scanning-electron- and confocal-optical-microscopic observations revealed that microgratings were formed inside the sample at a depth of similar to5 mm from the top surface. Also, inside the SiO2 glass, three-dimensional periodic arrays of the grating and crossed-grating structures were fabricated. The present technique is a fast method that is applicable not only for encoding volume-type gratings inside all nonphotosensitive transparent dielectric materials, but also for fabricating optical devices such as distributed-feedback lasers and multilayered memories. (C) 2002 American Institute of Physics.