Phase-shifting interferometry based on the lateral displacement of the light source.

Area of Science:

• Optical Physics
• Interferometry
• Metrology

Background:

• Phase-shifting interferometry (PSI) is crucial for precise optical metrology.
• Traditional PSI methods often require complex or expensive phase-shifting mechanisms.

Purpose of the Study:

• To propose a simple, inexpensive optical setup for phase-shifting interferometry.
• To demonstrate an alternative method for inducing phase shifts using lateral displacement of a point laser source.

Main Methods:

• Modification of a Twyman-Green Interferometer.
• Inducing phase shifts via lateral displacement of the point laser source.
• Utilizing a generalized phase-shifting algorithm for phase recovery.

Main Results:

• Experimental validation of the theoretical explanation for phase induction.
• Successful recovery of phase shift and wrapped phase from interferograms.
• Demonstrated feasibility of the proposed PSI technique.

Conclusions:

• The proposed method offers a simple and cost-effective approach to PSI.
• Lateral laser source displacement is a viable technique for phase shifting.
• The generalized algorithm effectively handles arbitrary and unknown phase shifts.