A high accuracy measurement method based on vortex polar axis rotation phase-shifting interferometry (VPAR-PSI)

Area of Science:

• Optics and Photonics
• Interferometry
• Metrology

Background:

• Traditional Phase Shifting Interferometry (PSI) methods often suffer from deviations and non-linearity due to grey-scale modulation.
• Accurate phase shift measurement is crucial for high-precision metrology and optical component characterization.

Purpose of the Study:

• To introduce a novel phase shift measurement technique, Vortex Beam Polar Axis Rotation Phase Shifting Interferometry (VPAR-PSI), for enhanced precision.
• To overcome the limitations of grey-scale modulation in conventional PSI.

Main Methods:

• Utilizing the unique characteristics of vortex beams to introduce phase shifts directly via polar axis rotation.
• Implementing VPAR-PSI for simulation, sample, and comparative experiments against traditional PSI.

Main Results:

• VPAR-PSI demonstrated high phase-shifting and demodulation accuracy in simulations and experiments.
• Comparative experiments showed VPAR-PSI significantly reduced envelope values, RMS, and standard deviation compared to conventional PSI.
• Mean envelope reduction of 1.4202λ and percentage decreases of ~59.7% in RMS and standard deviation were observed.

Conclusions:

• The VPAR-PSI technique offers superior accuracy and stability for optical component measurement.
• VPAR-PSI effectively mitigates deviations and non-linearity associated with grey-scale modulation.
• The proposed method represents a significant advancement in high-precision phase shift measurement.