Influence of Lens Systematic Errors on Autocollimator Angle Measurement: Theoretical and Experimental Explanations

Area of Science:

• Optical Engineering
• Metrology

Background:

• Autocollimators are essential for precise sensor calibration.
• Understanding systematic errors, including aberrations and assembly deviations, is key to enhancing autocollimator accuracy.
• The coupled effects of aberrations and assembly deviations on measurement accuracy require further investigation.

Purpose of the Study:

• To analyze the influence mechanism of systematic errors originating from the collimator objective on autocollimator measurement accuracy.
• To investigate the impact of aberrations and assembly deviations, and their combined effects.
• To define and quantify the sensitivity of assembly deviation.

Main Methods:

• Utilized ray tracing and aberration theory to analyze the influence of aberrations.
• Applied nodal wave aberration theory to study the effect of assembly deviation.
• Conducted experimental validation using a homemade autocollimator.

Main Results:

• Identified coma aberrations as the primary factor affecting accuracy.
• Found that assembly deviation's influence is related to aberrations under specific offsets (translational and rotational).
• Experimental results demonstrated a significant reduction in maximal yaw and pitch angle errors (from 2.09 to 1.41 arcsecs and 2.32 to 1.63 arcsecs, respectively).

Conclusions:

• Coma aberrations and assembly deviations significantly influence autocollimator accuracy.
• The defined sensitivity of assembly deviation (0.004 arcsec/micron) aligns with theoretical predictions.
• The findings provide a basis for improving autocollimator design and calibration for enhanced measurement precision.