COMPACT FPGA BASED MULTI-AXIAL INTERFEROMETER APPLIED IN A METROLOGICAL ATOMIC FORCE MICROSCOPE |
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| Sebastian Strube, Gabor Molnar, Hans-Ulrich Danzebrink |
- Abstract:
- For use in a new, metrological atomic force microscope (AFM) a highly compact interferometer, based on a modified homodyne Twyman-Green interferometer concept was developed at PTB. It is modular, measures displacement and tilt simultaneously, allows for traceability and an uncertainty in the Ångstrom range. A novel signal processing approach based on a field programmable gate array (FPGA) is employed, whereby a spatial interferogram is acquired by a high-speed line sensor and transformed into its frequency spectrum through a discrete Fourier transform. The AFM combines an FPGA for preprocessing, a digital signal processor (DSP) which runs the AFM control algorithm and a general purpose processor (GPP) for user-interface handling and mass data storage. The complete system allows for implementing a multitude of different AFM measuring modes, e.g. contact mode, intermittent contact mode using amplitude detection and phase detection or frequency tracking mode.
- Keywords:
- interferometry, FPGA, nanometrology, nanoscale, atomic force microscopy (AFM), nanopositioning, tilt measurement, distance measurement
- Download:
- IMEKO-TC14-2011-46.pdf
- DOI:
- -
- Event details
- IMEKO TC:
- TC14
- Event name:
- TC14 LMPMI Symposium 2011
- Title:
10th Symposium on Laser Metrology for Precision Measurement and Inspection in Industry
- Place:
- Braunschweig, GERMANY
- Time:
- 12 September 2011 - 14 September 2011