Farfield Scientific's novel Dual Path (slab waveguide) Interferometer
[DPI] quantifies chemical interactions on the surface of the slab
guide, by recording a far field proection of optical interference
effects. Farfield is a firm based in the UK with little visibility
stateside but the technology is quite practical and useful, and very
simple for studying for example biochemical affinity that is otherwise
tricky to quantify.
Check out the blog post at Wendman's Views on Nanotech - a blog about
practical commercially interesting innovations in nanotech devices and
instruments
http://mark-nano.blogspot.com/2006/09/farfield-scientifics-novel.html