NEAR-FIELDS · 2019. 8. 13. · evanescent fields λ FARFIELD NEARFIELD ... NEAR-FIELD OPTICAL...
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NEAR-FIELDS
Transcript of NEAR-FIELDS · 2019. 8. 13. · evanescent fields λ FARFIELD NEARFIELD ... NEAR-FIELD OPTICAL...
NEAR-FIELDS�
LIGHT SOURCES�
(visible light)�propagating fields�(invisible light)�
evanescent fields�
λ
FARFIELD�
NEARFIELD�
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. . . . .
λ NA
Resolution limited to ~λ/2 �
Δx = 0.61 NA λ
E. Abbe, Arch. Mikrosk. Anat. 9, 413 (1873) �
IMAGING �
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BLOOD STAINS ON HUMAN HAIR �
Source: CSI MIAMI �
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Ca2+ PROTEINS IN RED BLOOD CELLS�
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Ca2+ PROTEINS IN RED BLOOD CELLS�
λ/2 �
Diffraction Limit !! �
protein
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. . . . .
NA
λ
Δx = 0.61 NA λ
Δk 4π
Δp h
Diffraction limit = Uncertainty principle Resolution limited by ~λ/2
UNCERTAINTY PRINCIPLE�
Physics Today, July (2011)�
Δx Δp = 15.3 h /2 > /2 h
LIGHT SOURCES�
(visible light)�propagating fields�(invisible light)�
evanescent fields�
λ
FARFIELD�
NEARFIELD�
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VISIBLE AND INVISIBLE LIGHT�
(visible light)�propagating fields�
λ λ
(invisible light)�evanescent fields�
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near-field� rescuer�
FREEING THE NEARFIELD �
invisible light �
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λ
near-field � rescuer�
invisible light �
FREEING THE NEARFIELD �
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DEMO �
EVANESCENT WAVES ?�
TOTAL INTERNAL REFLECTION �
relative index of refraction �
ñ > 1 �plane wave�evanescent wave�
real�imaginary�
Glass-air interface : �
ñ < 1 �
Critical angle : �
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TOTAL INTERNAL REFLECTION (TIR)�
Appl. Opt. 33, 7995 (1994)�
: , � complex ! �
Goos-Hänchen shift �
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FRUSTRATED TOTAL �INTERNAL REFLECTION �
�
�
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HOMEWORK� �
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. . . . .
NA
λ
Δx = 0.61 NA λ
Δk 4π
Δp h
Diffraction limit = Uncertainty principle Resolution limited by ~λ/2
UNCERTAINTY PRINCIPLE�
Physics Today, July (2011)�
Δx Δp = 15.3 h /2 > /2 h
SUB-WAVELENGTH LOCALIZATION �
<< λ
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. . . . .
λ
Resolution is diffraction unlimited !!
antenna
Δd << λ
NA
evanescent waves: Δk > NA 4π / λ ~ 4π / Δd
UNCERTAINTY PRINCIPLE�
Physics Today, July (2011)�
NEAR-FIELD OPTICAL MICROSCOPY�
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Rep. Prog. Opt. 50, 137-180 (2007)�Physics Today, July (2011)�
A. EINSTEIN (1928) �
SYNGE DEVELOPS REVISED CONCEPT (APERTURE) ! �
E.H. Synge, Phil.Mag. 6, 356 (1928)�
SYNGE’s PUBLICATION ! �
Rep. Prog. Opt. 50, 137-180 (2007)�Physics Today, July (2011)�
2001 FUJI-XEROX PATENT�
Rep. Prog. Opt. 50, 137-180 (2007)�Physics Today, July (2011)�
U. Ch. Fischer and D. W. Pohl, �Phys. Rev. Lett. 63, 458, 1989.���
J. Wessel, �JOSA B 2, 1538, 1985.���
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IMAGING OF SINGLE Ca+ ION CHANNEL �PROTEINS IN ERYTHROCYTE MEMBRANES�
C. Hoeppener
Nano Lett. 8, 642 (2008)�
IMAGING OF SINGLE Ca+ ION CHANNEL �PROTEINS IN ERYTHROCYTE MEMBRANES�
C. Hoeppener
Nano Lett. 8, 642 (2008)�
15 nm�
PRL 109, 017402 (2012)�
LOCALIZATION OF LIGHT�
LOCALIZATION OF FIELDS�
∼ λ/2
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STRONGLY FOCUSED LIGHT�
Applications: (1) High NA objectives, (2) Solid Immersion Lenses, (3) Optical Tweezers, �" (4) Single Molecule Spectroscopy, (5) Confocal Microscopy, …�
Gaussian Beams�(paraxial optics, do not exist) �
Rigorous Beams�(angular spectrum representation) �
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STRONGLY FOCUSED LIGHT�EXAMPLES: �
www.nano-optics.org �
LONG-RANGE SUBSURFACE IMAGING �OF INTEGRATED SILICON DEVICES �
Conventional 50X objective + AR! 10X objective with NAIL!
λ = 1064 nm λ = 1064 nm
Selim Unlu, Boston University�
www.nano-optics.org �
SUB-WAVELENGTH LOCALIZATION �
<< λ
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