Development of an angular displacement measurement technique through birefringence heterodyne interferometry

Area of Science:

• Optics and Photonics
• Measurement Science and Instrumentation

Background:

• Accurate angular displacement measurement is crucial in various scientific and industrial applications.
• Existing sensors often face limitations in range, resolution, or environmental robustness.

Purpose of the Study:

• To develop a high-resolution angular displacement sensor for large-range measurements.
• To leverage birefringence and heterodyne interferometry for enhanced performance.

Main Methods:

• Utilized the birefringence effect and phase detection of heterodyne interferometry.
• Employed an innovative sandwich optical design for high system symmetry and simple operation.
• Implemented a common-path optical arrangement for improved stability.

Main Results:

• Achieved a measurement range exceeding 26°.
• Demonstrated a high measurement resolution of approximately 1.2 × 10⁻⁴°.
• Exhibited superior immunity to environmental disturbances due to the common-path design.

Conclusions:

• The proposed angular displacement sensor offers a promising solution for precise large-range angle measurements.
• The innovative optical design and measurement principle contribute to high accuracy and stability.
• The sensor is well-suited for applications demanding robust performance in challenging environments.