Nanometrological AFM with high-resolution interferometers can be used for a wide-ranged measurements and be
traceable to the unit of length, but such problems as reduction of measuring uncertainty, correction of complex
nonlinearity error and advancing of repeatability restrict the application of MAFM. This paper presents the design of
metrological AFM based on double F-P interferometer in XYZ directions, which consists of one He-Ne laser, one '1 x 3'
fiber splitter and four self-focused lens instead of three sets of He-Ne laser. This design can not only avoid the traceable
error caused by different optical sources in three directions, but also improve the resolution of the measurement through
the transfer of nano-dimension to a pair of fundamental frequency pulse interval, while external noise and disturbance
caused by outside environment are dramatically eliminated using double F-P interferometers of the same cavity length
and material. Nano-dimensional measurement and stability test have been successfully accomplished with double F-P
system in X or Z direction with measurement sensitivity of &lgr;/2000nm , which meets the requirement of nanometrology.
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