Optical Sensor for Scanning Angle of Micromirror with Improved 2D Calibration Method.

Area of Science:

• Optical sensing technologies
• Microsystems engineering

Background:

• Optical angle sensors offer advantages over piezoresistive sensors for micromirrors, particularly in temperature stability.
• Existing optical sensors face challenges with non-measured axis interference and linearity.

Purpose of the Study:

• To introduce and validate a sub-region calibration method for optical angle sensors.
• To address linearity issues and interference from unmeasured axes in optical angle sensing.

Main Methods:

• Developed a mapping surface linking output signal offsets to input angles.
• Implemented a sub-region grid with bilinear interpolation for angle calculation.
• Utilized scaling and floor functions for efficient grid area assignment.

Main Results:

• The sub-region calibration method significantly improves sensor linearity.
• Measurement errors were maintained below 0.01° within a ±8° operating range.
• Experimental validation confirmed the method's effectiveness using a custom optical sensor and rotating stage.

Conclusions:

• The proposed sub-region calibration method effectively mitigates interference and linearity issues in optical angle sensors.
• This technique enhances the suitability of optical sensors for precise micromirror applications.
• The method offers a robust solution for accurate angle detection in challenging environments.