posted on 2012-08-08, 00:00authored byM. Khorasaninejad, N. Abedzadeh, J. Walia, S. Patchett, S. S. Saini
Vivid colors are demonstrated in silicon nanowires with
diameters
ranging from 105 to 346 nm. The nanowires are vertically arranged
in a square lattice with a pitch of 400 nm and are electromagnetically
coupled to each other, resulting in frequency-dependent reflection
spectra. Since the coupling is dependent on the refractive index of
the medium surrounding the nanowires, the arrays can be used for sensing.
A simple sensor is demonstrated by observing the change in the reflected
color with changing refractive index of the surrounding medium. A
refractive index resolution of 5 × 10–5 is
achieved by analyzing bright-field images captured with an optical
microscope equipped with a charge coupled device camera.