A low noise all-fiber interferometer for high resolution frequency modulated atomic force microscopy imaging in liquids

作者：Rasool Haider I^*; Wilkinson Paul R; Stieg Adam Z; Gimzewski James K

来源：Review of Scientific Instruments, 2010, 81(2): 023703.

DOI：10.1063/1.3297901

• atomic force microscopy
• Fabry-Perot interferometers
• fibre optic sensors
• frequency modulation
• mica
• optical noise

We have developed a low noise all-fiber interferometer for use as the deflection sensor in liquid environment frequency modulated atomic force microscopy (FM-AFM). A detailed description and rationale for the choice of the critical components are provided along with the design of a simple alignment assembly. The optimization of the deflection sensor toward achieving the highest possible sensitivity and lowest deflection noise density is discussed in the context of an ideal interference cavity. Based on the provided analysis we have achieved deflection noise densities of 2 fm/root Hz on commercially available cantilevers in both ambient and liquid environments. The low noise interferometer works without the need for differential detection, special focusing lenses, or polarization sensitive optics, dramatically simplifying measurements. True atomic resolution imaging of muscovite mica by FM-AFM in water is demonstrated using the developed deflection sensor.

• 出版日期2010-2