Real-time FPGA-LabVIEW homebuilt system for noise reduction in AFM imaging

Abstract

Atomic force microscopy (AFM) probe vibration monitoring is essential for achieving accurate nanoscale imaging and reliable signal interpretation. This paper presents a low-noise vibration detection method based on a real-time FPGA-LabVIEW homebuilt system. The FPGA receives signals from a quadrant photodiode (QPD), performs analog-to-digital conversion and parallel processing, and integrates cascaded digital filters for noise reduction. A finite impulse response (FIR) low-pass filter extracts the static spot position, while an infinite impulse response (IIR) band-pass filter preserves the probe’s resonance vibrations. Compared with conventional analog detection, the proposed system reduces background noise by approximately 50% (measured as 50.23%), enhances the signal-to-noise ratio (SNR) from 15 dB to 20 dB, and maintains FPGA signal-processing latency below 5 μs. This work demonstrates that the proposed real-time FPGA-LabVIEW AFM noise optimization system significantly improves signal-to-noise ratio and real-time performance, providing a practical solution for high-precision, low-noise AFM imaging.

Keywords

atomic force microscopy (AFM) / FPGA-LabVIEW homebuilt system / real-time processing / noise reduction / digital filters

Acknowledgement

This work was supported by the National Key R&D Program of China (No. 2022YFC2204104), NSFC Projects of International Cooperation and Exchanges (No.62220106012), and Key Lab of Quantum Sensing and Precision Measurement, Shanxi (No.201905D121001)

Declaration of conflicting interests

The authors have no conflict of interests related to this publication.

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