  Ultrafast lasers have revolutionized material processing, opening a wealth of
new applications in many areas of science. A recent technology that allows the
cleaving of transparent materials via non-ablative processes is based on
focusing and translating a high-intensity laser beam within a material to
induce a well-defined internal stress plane. This then enables material
separation without debris generation. Here, we use a non-diffracting beam
engineered to have a transverse elliptical spatial profile to generate high
aspect ratio elliptical channels in glass of dimension 350 nm x 710 nm, and
subsequent cleaved surface uniformity at the sub-micron level.
