Applications of negativepermittivity materials to subwavelength imaging and nanotechnologies - PowerPoint PPT Presentation

Title: Applications of negativepermittivity materials to subwavelength imaging and nanotechnologies


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Nanophotonic structures in mid-IR based on SiC
films Theory and Experiment Dmitriy Korobkin,
Yaroslav Urzhumov, Burton Neuner III, and Gennady
Shvets (Physics Department, UT Austin)
SiC-based Nano-structures
Application Sub-surface Imaging
Sub-wavelength Antennas in IR Nano-Holes

• SiC Super-lens with objects
• Slits, 450 nm wide
• Circular holes of different
• diameter (0.5, 0.8, 1.2 micron)
• Custom objects word NANO
• (HAHO in Cyrillic)

(with Taubner and Hillenbrandt, MPQ/Munich)
2. Regular 2D arrays of holes in a SiC membrane.
3. 2D lattice of silver posts on SiC substrates
cm-1
pattern on bottom
NSOM image from top
Image Diagnostics in Far-Field
Experiment enhanced laser absorption at w 850
cm-1 by perforated SiC membrane SiC thickness
458 nm Hole diameter 1 mm Hole spacing
7 mm
Backside diagnostic slits
Super-lensing e(l0) -ed
E-field enhancement
In-phase diagnostic slits HIGH TRANSMISSION
Out-of-phase diagnostic slits LOW TRANSMISSION
Sub-surface Imaging of Single Holes
Fabrication Super-Lens with Slits under SEM
SEM image
Next step to optical NIM ? clusters of closely
spaced nano-holes give magnetic response gt true
negative index material !
15.0 keV Scanning Electron Microscope image Lens
dimensions 200nm SiO2 - 400nm SiC - 200nm
SiO2 Slit spacing 2.5 micron Slit width 500
nm Full size 300 x 300 mm
Theory electrostatic resonance of a single hole
in SiC (3D simulation)
small hole 500nm
Fabrication Silver posts on a 3C-SiC membrane
l10.62 mm
l11.03 mm
l10.85 mm
l9.27 mm

• Resolution of l/20
• Increased range of frequencies for imaging ?
  amplitude or phase
• Higher resolution with phase imaging ? less
  sensitive to topography

Quad 1 Period 12 mm f 3 mm
Quad 2 Period 5 mm f 2 mm
amplitude images
phase images
Experiment FTIR Microscopy Reveals Near-Field
Image
2D Lattice of Holes in SiC Membrane
10 nm Cr 200 nm Ag
450 nm thick SiC membrane
Quasistatic 2D Theory electrostatic resonances
of silver posts on SiC
2D array of holes diameter 1 mm periodicity 5,
7, or 12 mm diameter 2 mm periodicity 5 or 7 mm
electric field2 (intensity)
potential
e lt 0
Fabricated by FIB drilling of free SiC membrane
In- and out-of-phase grid transmission is usually
roughly equal, but differs by x10 at the
super-lensing frequency