Polarization sensitive phase-shifting Mirau interferometry using a liquid crystal variable retarder.

Area of Science:

• Optics and Photonics
• Interferometry
• Liquid Crystal Devices

Background:

• Phase-shifting interferometry (PSI) is crucial for precise optical metrology.
• Traditional PSI methods often require mechanical scanning, limiting speed and stability.
• Polarization-based PSI offers an alternative approach to introduce phase shifts without mechanical movement.

Purpose of the Study:

• To develop an all-optical, motionless system for polarization sensitive phase-shifting (P-S) interferometry.
• To accurately implement phase shifts using a liquid crystal variable retarder (LCVR).
• To evaluate the system's accuracy for quantitative phase reconstruction.

Main Methods:

• An all-optical, motionless setup utilizing a liquid crystal variable retarder (LCVR) for phase shifting.
• The LCVR introduces computer-controlled phase retardance between orthogonal polarization states.
• The P-S interferometry is implemented in a polarization-adapted common-path Mirau interferometer, with extensions to Michelson and Linnik configurations.

Main Results:

• Theoretical examination of quantitative phase reconstruction accuracy.
• Experimental demonstration of reducing optical path difference error below 1/200 wavelength.
• Validation of the LCVR's capability for precise, computer-controlled phase shifts.

Conclusions:

• The proposed polarization sensitive phase-shifting interferometry offers a stable and accurate method for optical measurements.
• The use of LCVRs provides a versatile platform for advanced interferometric techniques.
• This technique has significant potential for applications requiring high-precision, non-contact optical measurements.