Grating (Moiré) Microinterferometric Displacement/Strain Sensor with Polarization Phase Shift

Area of Science:

• Optics and Photonics
• Mechanical Engineering
• Materials Science

Background:

• Grating (moiré) interferometry is a key technique for full-field in-plane displacement and strain measurement.
• Conventional waveguide interferometer heads have limitations in automatic fringe pattern analysis.

Purpose of the Study:

• To propose and verify a modified waveguide interferometer head for grating interferometry.
• To enable automatic fringe pattern analysis using polarization fringe phase shift.
• To demonstrate in-plane displacement/strain sensing with the modified head.

Main Methods:

• Theoretical analysis of a modified waveguide interferometer head.
• Implementation of polarization fringe phase shift for fringe analysis.
• Experimental verification of the proposed interferometer design.
• Concept demonstration for in-plane displacement/strain sensing.

Main Results:

• Successful modification of a conventional waveguide interferometer head.
• Demonstration of polarization fringe phase shift for automatic analysis.
• Experimental validation of the theoretical considerations.
• Proof of concept for in-plane displacement/strain sensing.

Conclusions:

• The proposed modification enhances grating interferometry by enabling automatic fringe pattern analysis.
• The modified waveguide interferometer head is effective for precise in-plane displacement and strain measurements.
• This advancement offers a more efficient approach to optical metrology.