A motion characteristics modeled angular position sensor by nonlinear transfer of differential capacitance for...

Area of Science:

• Optics and Photonics
• Sensor Technology
• Mechanical Engineering

Background:

• Resonant miniaturized scanning mirrors (M-SMs) require precise angular position sensing.
• Conventional sensors have limited bandwidth and accuracy for dynamic M-SM applications.
• Existing methods struggle with nonlinear errors and limited measurement ranges.

Purpose of the Study:

• To develop a high-bandwidth, high-accuracy angular position sensor (APS) for M-SMs.
• To overcome limitations of conventional sensors in detecting dynamic angular changes.
• To improve the performance of laser components and systems.

Main Methods:

• Utilized differential variable capacitance for sensing.
• Modeled M-SM motion as simple harmonic motion for capacitance conversion.
• Employed space coordinate transformation to address sensor non-parallelism.
• Developed a 2D nonlinear angle transfer function to correct for large angle errors.

Main Results:

• Achieved measurement accuracy better than 0.014°.
• Expanded the measuring range from ±0.5729° to ±5.026°.
• Demonstrated high sampling rates (1473.6x and 539.4x higher than conventional).
• Proposed capturing and tracking modes with 0.017° accuracy for real-time monitoring.

Conclusions:

• The developed APS significantly enhances detectable bandwidth and angular measurement accuracy for M-SMs.
• The sensor's capabilities are crucial for advancing laser components, including LiDAR systems.
• This technology promises improved beam pointing accuracy and resolution in optical systems.