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Near Field Scanning Optical Microscopy (NSOM, SNOM, NFOM) Stephanie Pruzinsky Group Meeting, June 6, 2002. 0.61 n sin 0. d =. Near-Field v. Far-Field . Near-Field (Evanescent). Light with spatial frequencies are present in the tip but decay within one wavelength
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Near Field Scanning Optical Microscopy (NSOM, SNOM, NFOM) Stephanie Pruzinsky Group Meeting, June 6, 2002
0.61 n sin 0 d = Near-Field v. Far-Field Near-Field (Evanescent) Light with spatial frequencies are present in the tip but decay within one wavelength dmin ~ 1 – 20 nm has been reported dmin ~ 50 – 100nm is more common Far-Field (Diffraction Limited) dmin ~ /2 - http://www.nrel.gov/sss/nsom.html
WITEC NSOM Setup http://www.witec.de/snom.html
NSOM Probe Techniques Aperture Apertureless STOM
NSOM Aperture Probes Chemical Etching Fiber-Pulling Evanescent Decay Aluminum Deposition 300 nm 300 nm
WITEC Microfabricated NSOM Probes wafer with 228 tips Si cantilever hollow Al pyramid tip ~ 100 nm http://www.witec.de/snom.html
NSOM Applications • Fluorescence imaging • tagged in situ biological samples • phase-separated or patterned films and monolayers • single dye molecules • Microspectroscopy • quantum dots • nanoparticles • plasmonic crystals • photonic crystals • Laser ablation • localized MALDI mass spectrometry • Photolithography, localized photochemistry…
NSOM Fluorescence Imaging of Single Dye Molecules 0˚ 2.1˚ 13.5˚
1 µm NSOM of 2D Photonic Crystals 100 nm