Small angular displacement measurement based on an autocollimator and a common-path compensation principle
1State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310027, China.
The Review of Scientific Instruments
|February 8, 2013
Summary
A new method uses an autocollimator and common-path compensation for precise small angular displacement measurement. This technique significantly improves measurement stability and resolution, achieving high accuracy for sensitive applications.
Area of Science:
- Optics and Measurement Science
Background:
- Accurate measurement of small angular displacements is critical in various scientific and engineering fields.
- Traditional methods often face limitations in resolution and stability due to environmental interferences.
Purpose of the Study:
- To propose and verify a novel method for small angular displacement measurement.
- To enhance measurement resolution and system stability using a common-path compensation principle.
Main Methods:
- Developed a measurement method integrating an autocollimator with a common-path compensation principle.
- Utilized a single Charge-Coupled Device (CCD) detector for beam spot displacement detection.
- Analyzed the principles of angular displacement measurement and common-path compensation.
- Conducted experiments to validate measurement feasibility, resolution, and compensation effectiveness under various interference conditions.
Main Results:
- Achieved a high linear correlativity of 0.99996 between beam spot displacement and angular displacement.
- Demonstrated a measurement resolution of approximately 0.03 arcseconds.
- Showcased significant improvements in angular drift reduction: 25.0%–80.0% in the x-direction and 28.2%–95.6% in the y-direction due to compensation.
Conclusions:
- The proposed novel method effectively measures small angular displacements with high accuracy and resolution.
- The common-path compensation principle significantly enhances system stability by mitigating environmental and system interferences.
- This technique offers a robust solution for applications demanding precise angular metrology.
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