Near-field optical microscopy in liquids

Abstract

The scanning near-field optical microscopy imaging of specimens in liquid and of cultured cells in aqueous solutions is reported. A scanning near-field optical/atomic-force microscope (SNOM-AFM) was developed, in which the scanning of an optical-fiber probe cantilever over the specimen was controlled by noncontact mode AFM (dynamic mode AFM). This imaging mode reduces damage to the probe and soft specimens. The resonant frequency of the probe cantilever decreased 20% to ≊14 kHz and the Q factor decreased by a factor of 8 to ≊30 in water, compared with these values in air, which was sufficient to perform SNOM-AFM imaging in liquid.

Evaluation of thermal evaporation conditions used in coating aluminum on near-field fiber-optic probes

“…Recent applications include studies on single molecules at room temperature, [4][5][6][7] aggregates, 8,9 quantum well devices, [10][11][12] and biological systems both dry and in aqueous environments. [13][14][15][16] The results from these studies have illustrated the unique information accessible with this optical technique.…”

Measurement of photo‐patterned surface potential of Alq3 thin films by Kelvin‐force microscope together with near‐field optical stimulation

“…Optical fiber probes (SII NanoTechnology, Inc., slim bent probe) [6,7] were used for this purpose. The fiber probes had a thin and bent part at one end, with 30-40 µm in diameter, which mechanically vibrates to work as a cantilever.…”

High‐speed scanning by dual feedback control in SNOM/AFM

“…We have also developed a SNOM controlled by an AFM (SNOM/AFM) (Muramatsu et al, 1995a(Muramatsu et al, , 1995b(Muramatsu et al, , 1997(Muramatsu et al, , 1998. However, imaging at a high-scanning rate over large scanning areas is desirable because present systems take too long to image a sample.…”