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SUMMARY:Electromagnetic metasurfaces – from butterflies to battleships -
  Professor J Roy Sambles ( School of Physics\, Exeter University)
DTSTART:20151126T190000Z
DTEND:20151126T203000Z
UID:TALK60792@talks.cam.ac.uk
CONTACT:Dr. Andrew Clarke
DESCRIPTION:Question:  	What do graceful flickering vividly iridescent tro
 pical butterflies have in common with dull grey ponderous battleships?  \n
 \nAnswer: 	Structured materials giving rather special electromagnetic resp
 onse.\n\nTaking little other than common cuticle\, loaded with a small amo
 unt of melanin\, butterflies have evolved some stunning microstructures (m
 etasurfaces) in their wing scales. These structured surfaces\, often only 
 microns thick\, act as selective reflectors and polarizers as well as bein
 g sometimes very strong scatterers (white) or very strong absorbers (black
 ) of electromagnetic radiation. This use of structure in nature to give st
 riking effects when interacting with visible radiation is of course limite
 d to dielectrics. Synthetic structures may also incorporate metals. Surfac
 e structured metals\, metasurfaces\, can lead to unexpected effects: for e
 xample selective absorption\, even at long wavelengths where metals are ex
 pected to behave as almost perfect mirrors\, or even negative refraction. 
 \nThis talk will illustrate the wonderful structural colours of butterflie
 s and will also explore some recent developments in structured metals\, me
 tamaterials and metasurfaces  which have surprising properties at microwav
 e frequencies. 
LOCATION:Schlumberger Cambridge Research
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