Reported by optic.org
German researchers have used an ultrashort pulsed laser to create subsurface nanostructures in a sapphire crystal. The team believes that the techniques could be used to fabricate microfluidic devices as well as 3D photonic structures. (Optics Express 16 1517.)
SEM images of the entrance of the modified and etched channel directly after etching (left) and cross section of hollow nanoplanes in 500 μm depth of the same track. Laser beam propagated from top to bottom, three parallel scans with an offset of 3 μm, focused with NA=0.55, f=500 kHz, P=450 mW.