An optically actuated surface scanning probe.
Opt Express
; 20(28): 29679-93, 2012 Dec 31.
Article
en En
| MEDLINE
| ID: mdl-23388796
We demonstrate the use of an extended, optically trapped probe that is capable of imaging surface topography with nanometre precision, whilst applying ultra-low, femto-Newton sized forces. This degree of precision and sensitivity is acquired through three distinct strategies. First, the probe itself is shaped in such a way as to soften the trap along the sensing axis and stiffen it in transverse directions. Next, these characteristics are enhanced by selectively position clamping independent motions of the probe. Finally, force clamping is used to refine the surface contact response. Detailed analyses are presented for each of these mechanisms. To test our sensor, we scan it laterally over a calibration sample consisting of a series of graduated steps, and demonstrate a height resolution of â¼ 11 nm. Using equipartition theory, we estimate that an average force of only â¼ 140 fN is exerted on the sample during the scan, making this technique ideal for the investigation of delicate biological samples.
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Óptica y Fotónica
Idioma:
En
Revista:
Opt Express
Asunto de la revista:
OFTALMOLOGIA
Año:
2012
Tipo del documento:
Article
Pais de publicación:
Estados Unidos