Micro-/nano-photonic device structures: Analysis and applications in communications and sensing

The realisation of photonic devices that employ nanometre-scale structuring – and that meet the vital requirement for nanometric levels of precision in their fabrication – will lead to a number of interesting near-future applications. Very compact and power/energy efficient devices are now possible – and these devices can deliver the basic functionalities required in various situations, such as modulation, detection, switching and wavelength selection. Sufficiently fast non-linear behaviour promises to deliver “all-optical' functionality that will greatly enhance the processing capability in a variety of different optoelectronic/photonic systems – with, for example, phase-accurate translation of data channel frequencies via efficient four-wave mixing processes at much lower optical and electrical power levels than currently required. The use of sub-micrometre scale waveguide cross-sections in silicon or other high refractive index materials and/or slow light structures – together with carefully tailored dispersion properties – will enable this new wave of photonic device technology, with high-density integration becoming a reality, particularly when compact optical isolation is added.