Atomic layer deposition (ALD) has become a powerful tool for the fabrication of high quality 3-dimentional photonic crystals (PCs) from both inorganic (opal) and organic (holographically patterned polymer) templates [1,2]. With ALD, highly conformal films can be grown with a precision of 0.05 nm, which, when combined with the availability of a wide range of low temperature film growth protocols, enables a high degree of control over material and structural properties to precisely tune optical properties . Two-dimensional photonic crystals have been developed extensively for applications in optical interconnects, beam steering, and sensor devices; and are predominantly fabricated by electron-beam lithography. The optical properties of 2D photonic crystal slab waveguides are determined by the precision of the lithography process, with limited post fabrication tunability.
Graugnard, Elton; Gaillot, Davy P.; Dunham, Simon N.; Neff, Curtis W.; Yamashita, Tsuyoshi; and Summers, Christopher J.. (2006). "Photonic Band Tuning in 2D Photonic Crystals by Atomic Layer Deposition". 19th Annual Meeting of the IEEE Lasers and Electro-Optics Society, 2006. LEOS 2006., 763-764. http://dx.doi.org/10.1109/LEOS.2006.278973