Design of Atomic Force Microscope Photoelectric Sensing Circuit Based on Kalman Filter.

Area of Science:

• Atomic Force Microscopy
• Sensor Technology
• Signal Processing

Background:

• Noise in photoelectric sensing circuits limits atomic force microscopy (AFM) performance and intelligent applications.
• Existing methods struggle to effectively denoise signals without impacting sensor performance.

Purpose of the Study:

• To develop an improved atomic force microscope photoelectric sensing circuit.
• To enhance signal-to-noise ratio and reduce transmission attenuation.
• To improve dynamic AFM systems through integrated negative feedback control.

Main Methods:

• Embedding a Kalman filter algorithm into the photoelectric sensing circuit for signal denoising.
• Utilizing an STM32 microcontroller for analog-to-digital conversion to minimize signal distortion.
• Integrating the sensing circuit with negative feedback control for dynamic AFM operation.

Main Results:

• Achieved a detection limit of ±5 V and a rapid response time of approximately 10 µs.
• Covered a broad laser wavelength detection range from 100-1100 nm.
• Successfully improved the signal-to-noise ratio without compromising the photoelectric sensor's inherent performance.

Conclusions:

• The developed Kalman filter-based photoelectric sensing circuit effectively reduces noise in AFM systems.
• The integration enhances signal integrity and broadens the applicability of AFM, particularly in dynamic modes.
• This advancement paves the way for more sophisticated and intelligent AFM applications.