Abstract

General trends in designing photonic bandgap (PBG) materials are the approaching of the omnidirectionality of the stop-band and the incorporation of photonic crystals in optoelectronic devices. Where the light emission is concerned 3-dimensional photonic crystals possess the advantages of confining the emission in all directions and the possibility to operate with a higher emission intensity as compared with those of lower dimensionality. However, massive opal-based photonic crystals suffer a high level of structural defects and their replicas appear too fragile to be processed further. Thin film opal-like package of polymeric balls prepared on substrates pose a sound alternative to bulk opals, because only a few layers of scatterers are necessary to form a pronounced PBG in the case of high refractive index contrast (R1C). Generally, with the increase of the aspect ratio (area/thickness) a ball package acquires higher quality. The substrate not only helps to maintain the integrity of semiconductor replica, but can be also used to form other elements required for completing an optoelectronic device. Being made from PMMA balls polymeric opal templates allow the post-sedimentation lithographical shaping to form secondary structures, e.g. waveguides.

© 2000 IEEE