Generation of Photonic Crystal End Faces Using Laser Microfabrication

We present a number of laser microfabrication methods to generate high quality end faces of photonic crystal templates. We have produced opal templates of 1 m polystyrene spheres with 10-30 m thickness on glass substrates using the self-assembly technique. In order to gain access to the useable area in the centre of the polystyrene opals, we modified the glass substrates and the opals with pulsed ns and ps UV lasers. By writing micro grooves into the substrate, changing the wettability of the substrates surface, and by using micro stereo lithography to fabricate polymer structures on top of the substrates, we generated good quality crystal end faces accessible for direct fibre coupling. The polymer structures allowed us to gain control of the crystal orientation. We also used a UV laser to make the glass substrates hydrophilic, which is a necessary prerequisite for the crystal growth process.