Analysis of non-linearity in differential wavefront sensing technique.

Area of Science:

• Optics and Photonics
• Optical Metrology

Background:

• Differential Wavefront Sensing (DWS) is crucial for high-precision optical measurements.
• Understanding non-linearity in DWS is essential for accurate interferometry.

Purpose of the Study:

• To derive and validate an analytical model for Gaussian Beam-based DWS.
• To investigate the influence of beam clipping and beam walking on DWS non-linearity.

Main Methods:

• Derivation of an analytical model for DWS using Gaussian Beam propagation.
• Numerical simulation and comparison with experimental interference signals from a quadrant photodiode.
• Analysis of beam clipping and beam walking effects on detection non-linearity.

Main Results:

• The analytical DWS model was successfully derived and verified against numerical methods.
• Both model and simulation indicate milli-radians level non-linearity in DWS detection.
• Increased beam clipping reduces DWS non-linearity; beam walking has negligible impact.

Conclusions:

• The developed analytical model accurately represents DWS behavior.
• Beam clipping is a key factor influencing DWS non-linearity and should be managed.
• Beam walking can be disregarded in laser interferometer applications utilizing DWS.