1. Near Field Scanning Optical Microscopy (NSOM, SNOM, NFOM) Stephanie Pruzinsky Group Meeting, June 6, 2002

2. Near-Field v. Far-Field 0.61 n sin 0 d = Far-Field (Diffraction Limited) d min ~ /2 - Near-Field (Evanescent) Light with spatial frequencies are present in the tip but decay within one wavelength d min ~ 1 – 20 nm has been reported d min ~ 50 – 100nm is more common http://www.nrel.gov/sss/nsom.html

3. Typical NSOM Setup

4. WITEC NSOM Setup http://www.witec.de/snom.html

5. NSOM Probe Techniques ApertureAperturelessSTOM

6. NSOM Aperture Probes 300 nm Fiber-Pulling Chemical Etching Aluminum Deposition Evanescent Decay

7. WITEC Microfabricated NSOM Probes wafer with 228 tips Si cantilever hollow Al pyramid tip ~ 100 nm http://www.witec.de/snom.html

8. 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…

9. NSOM Fluorescence Imaging of Single Dye Molecules 0˚0˚ 2.1˚ 13.5˚

10. NSOM Spectroscopy of Quantum Dots

11. NSOM of 2D Photonic Crystals 1 µm 100 nm