Novel method for fabrication of volume 2D photonic crystals

Photonic crystals are wavelength-scale periodic structures built from dielectrics with different refractive indexes As standard 2D photonic crystals are fabricated by lithographic methods, but in this case only planar structure can be obtained. We have adapted stack and draw technique that is usually used for photonic crystal fiber fabrication to develop volume 2D photonic crystals. Technology allows fabrication of high contrast structures with air holes as well as low contrast solid-all structures where air holes are replaced with glass micro rods of refractive index. Use of soft glasses with a high difference in refractive index allows development of a structure where partial photonic band gap exists. The proposed method offers possibility of fabrication volume 2D photonic crystal with a diameter in the order of I min and height of a few mm. Large area photonic crystals are very attractive as new optical material named 'photonic glass' with built-in photonic bandgap functionality. Preliminary fabrication test were performed for two pairs of soft glasses NC21/F2 and SK222/Zr3. The considered glasses are thermally matched and are synthesized in-house except of F2 glass (standard Schott glass). Obtained structures are regular with some defects on the borders between intermediate performs. Some glass diffusion is observed between Zr3 and SK222 glasses. With this technique a 2D photonic crystal with a hexagonal lattice was fabricated with a pair of soft glasses SK222 and Zr3. Microrod diameter is 749nm and lattice constant I I 10 nm. Photonic crystal consists of 166421 elements (425 elements on diagonal) and its total surface is about field -0,178mm2.