Nanophotonics is the interaction of light with structures on the order of, or smaller than the wavelength of light.  At these length scales optical structures can be engineered to manipulate light: to diffract it, scatter it, concentrate it and even to bend it.  Recent advances in large scale fabrication of optical nanostructure arrays, for example nanoimprint lithography and holographic techniques, have meant that nanophotonics has found many new applications: from improving the sensitivity and selectivity of sensors and photodetectors, to increasing the efficiency of light harvesting for photovoltaics.  

For research purposes rapid prototyping of different geometries is highly desirable.  The standard way of fabricating nanophotonic structures in the lab is by electron beam lithography: writing patterns in a special resist with a focused beam of electrons.  Electron beam lithography (EBL) allows the flexibility to design and realise a wide range of nanostructures, but there is a catch: it is very slow.  For the types of patterns used in many optoelectronic applications, we are typically limited to array sizes of a few 10s to 100s microns square.  These size restrictions make it challenging to optically characterise EBL fabricated structures.

The goal of this project is to design, build and test an optical set up to measure the reflection and transmission of small area, i.e. a few 10s – 100s of microns square, nano-patterened areas.  This set-up will be a critical component of the new Nano-photonics Characterisation Lab in room E135 of the Engineering building, being set up by Dr Tom White and Dr Fiona Beck as part of their research on nanostructured optoelectronics.