Meta-Screen for High Resolution Optical Microscopy

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Meta-Screen for High Resolution Optical Microscopy

• Yan Wang, Amr S. Helmy, George V.
  Eleftheriades
• University of Toronto

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Overview

• Background
• Conventional optical microscope and its
  resolution limit
• Development in various high resolution microscopy
  technologies and their pros and cons.
• Scanning near-field optical microscopy (SNOM)
• Basic operating principles and drawbacks.
• Theory of meta-screen
• Improves the current SNOM resolution
• Design principles and performances
• Conclusion

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Background

• Optical microscopy seeing things with light
• Conventional compound optical microscopes

Nikon Eclipse 600 transmitted/reflected light
microscope 
An 1879 Carl Zeiss Jena Optical microscope
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Background (contd)

• Resolution limit of conventional optical
  microscopes
• Abbeys diffraction limit (200nm for the visible
  spectrum)

Propagating waves e-jßz
Toronto
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May 6, 2010
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Background (contd)

• Efforts in achieving high-resolution (beyond the
  diffraction limit)
• Electron microscope (TEM, SEM and REM etc.)
• Atomic force microscope (AFM)
• Pendrys perfect lens (meta-material
  application)

Jason Palmer, BBC news, Friday, 28 August 2009,
Single molecules stunning image
J.B. Pendry, Negative refraction makes a perfect
lens Phys. Rev. Lett. 85, 18 (2000).
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SNOM

• Scanning near-field optical microscope

WiTech alpha300S Scanning Near-field Optical
Microscope, ?lm, Germany

• Aperture probe limits resolution
• Operates in the near-field
• Does not depend on the wavelength of the
  illuminating light
• Suffers tremendous power loss

Human leucocyte
SPP propagation
Toronto
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May 6, 2010
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Meta-screen

• Improve the focusing ability of the aperture
  (multi-aperture approach)
• Circular aperture vs. slot aperture
• Single-slot vs. multi-slot

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Meta-screen

• Multi-slot metallic transmission screen
  (Meta-Screen)

Toronto
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May 6, 2010
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Meta-screen (contd)

• Meta-screen improves near-field focusing

Y. Wang et. al., Plasmonic meta-screen for
alleviating the trade-offs in the near-field
optics , Optics Express, 17, 12351-12361 (2009)  
Toronto
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May 6, 2010
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• Thank you!