Digital error-signal extraction technique for real-time automatic control of optical interferometers

Area of Science:

• Optics and Photonics
• Control Systems Engineering
• Experimental Physics

Background:

• Optical interferometers require precise control for accurate measurements.
• Existing methods for extracting error signals can be limited in performance and applicability.
• Automatic control of interferometers is crucial in scientific research and industrial applications.

Purpose of the Study:

• To develop an efficient and robust method for extracting longitudinal error signals in optical interferometers.
• To extend the applicability of error signal extraction to systems spanning hundreds of fringes.
• To digitally implement and validate the proposed method in a real-world application.

Main Methods:

• Utilizing classic modulation techniques (e.g., phase, mechanical modulation).
• Leveraging information exclusively from the output photodiode to enhance performance.
• Implementing a modular hardware and software architecture for digital processing.

Main Results:

• Demonstrated an efficient and robust method for longitudinal error signal extraction.
• Successfully applied the method to automatic control of a suspended Michelson interferometer.
• Showcased the feasibility and good performance of the digital implementation.

Conclusions:

• The developed method provides an effective solution for automatic control of optical interferometers.
• The technique offers improved performance and broader applicability compared to traditional methods.
• Digital implementation ensures robustness and facilitates integration into complex optical systems.