T. J. Constant, P. Vukusic, A. P. Hibbins and J. R. Sambles Appl. Phys. Lett. 106, 091106 (2015) http://dx.doi.org/10.1063/1.4914479 In periodic systems of low-symmetry, the Bragg condition for the complete interference of waves along the contour of the Brillouin zone (BZ) boundary is not generally satisfied. As a result, band-gaps do not necessarily occur at this … Continue reading Surface plasmons at the Brillouin zone boundary of an oblique lattice
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The calculation of the optical response of multilayer thin films
A little while ago (while avoiding my thesis), I wrote a small R package for the calculation of the optical response of multilayer thin films. It's called mlfilms and is avaliable on github. As a quick example, here is how you'd calculate and plot the reflection from a thin silver film through a prism. This … Continue reading The calculation of the optical response of multilayer thin films
Non-rectangular colourplots
When I started using R, one of the first things I wanted to do is make reliable colourplots. Colourplots are a way of representing 3D data as a 2D image, with the x and y coordinates representing variables and the z values represented as a colour. For simple colorplots, the image() function from the base … Continue reading Non-rectangular colourplots
Smartening up plots with ggplot
R is a wonderfully powerful tool for the production of publication-quality figures. The power of R to make these plots comes at a cost: with absolutley everything customizable the learning curve is steep, and the defaults can be ugly. Lets take a look at a default plot. x <- seq(0, 2 * pi, , 100) … Continue reading Smartening up plots with ggplot
Direct Mapping of Surface Plasmon Dispersion using Imaging Scatterometry
T. J. Constant, A. P. Hibbins, A. J. Lethbridge, J. R. Sambles, E. K. Stone, and P. Vukusic Appl. Phys. Lett. 102, 251107 (2013) http://dx.doi.org/10.1063/1.4812482 %5BPDF%5D The iso-frequency contours of diffracted surface plasmons on metallic bigratings have been directly recorded using imaging scatterometry. Metallic rectangular bigratings, formed of two “crossed” surface relief gratings, are used to demonstrate this measurement technique. By deepening one of the … Continue reading Direct Mapping of Surface Plasmon Dispersion using Imaging Scatterometry
Optical Excitation of Surface Plasmon Polaritons on Novel Bigratings
T. J. Constant Ph. D. Thesis (2013) http://hdl.handle.net/10871/9001 %5BPDF%5D This thesis details original experimental investigations in to the interaction of light with the mobile electrons at the surface of metallic diffraction gratings. The gratings used in this work to support the resultant trapped surface waves (surface plasmon polaritons), may be divided into two classes: ‘crossed’ bigratings … Continue reading Optical Excitation of Surface Plasmon Polaritons on Novel Bigratings
Surface Plasmons on Zigzag Gratings
T. J. Constant, T. Taphouse, H. J. Rance, S. C. Kitson, A. P. Hibbins, and J. R. Sambles Opt. Express 20, 23921-23926 (2012) http://dx.doi.org/10.1364/OE.20.023921 %5BPDF%5D Optical excitation of surface plasmons polaritons (SPPs) on a 'zig-zag diffraction grating' is explored. The fabricated silver grating consists of sub-wavelength grooves 'zig-zagged' along their length, providing a diffractive periodicity to visible … Continue reading Surface Plasmons on Zigzag Gratings
Surface Waves at Microwave Frequencies Excited on a Zigzag Metasurface
H. J. Rance, T. J. Constant, A. P. Hibbins, and J. R. Sambles Phys. Rev. B 86, 125144 (2012) http://dx.doi.org/10.1103/PhysRevB.86.125144 %5BPDF%5D Surface waves at microwave frequencies are excited on a zigzag metasurface formed from unit cells comprised of a pair of identical, alternately oriented, rhombic-shaped metal tubes. This particular symmetry leads to diffractive excitation, with polarization selectivity … Continue reading Surface Waves at Microwave Frequencies Excited on a Zigzag Metasurface
Thesis Diagrams
So, I'm writing my thesis at the moment, and invested some good procrastinating efforts to make sure my diagrams are consistent with my LaTeX thesis template. What I've learnt could be useful, so here it is; Graphs I do almost all of my data analysis using the fantastic (and free) R statistical package with RStudio. … Continue reading Thesis Diagrams
My My, It’s a Pi
So my Pi arrived yesterday, and I had a shot at setting it up as a media center using the XBMC-centric OS "Raspbmc". Overall it was pretty painless, but a few pitfalls still needed skirting so I thought I'd jot them down here. I also tried installing Arch Linux ARM, the recommended OS from the … Continue reading My My, It’s a Pi