High-accuracy wavefront sensing by phase diversity technique with bisymmetric defocuses diversity phase

Area of Science:

• Optics and Photonics
• Wavefront Sensing and Adaptive Optics

Background:

• Phase retrieval is crucial for optical system alignment and aberration correction.
• Common phase diversity (PD) algorithms use focused and one defocused image for phase estimation.
• Existing PD methods face limitations with large-scale and high-frequency wavefront aberrations.

Purpose of the Study:

• To develop and evaluate a novel phase diversity technique for enhanced wavefront sensing accuracy.
• To introduce the bisymmetric defocuses phase diversity (PD-BD) method.
• To compare the performance of PD-BD against conventional PD algorithms.

Main Methods:

• The study proposes PD-BD, utilizing image intensities from two symmetrical defocused planes.
• Performance is analyzed using the Cramer-Rao lower bound (CRLB) for statistical assessment.
• Numerical simulations and experimental verification are conducted to validate the method.

Main Results:

• PD-BD demonstrates statistically smaller CRLBs compared to conventional PD, indicating superior phase retrieval capacity.
• Numerical simulations confirm higher accuracy of PD-BD for large-scale and high-frequency wavefront aberrations.
• Experimental results further affirm the enhanced accuracy of PD-BD in wavefront sensing.

Conclusions:

• The bisymmetric defocuses phase diversity (PD-BD) method offers significantly improved accuracy in phase retrieval.
• PD-BD is particularly effective for challenging wavefront sensing applications with large-scale and high-frequency aberrations.
• This technique represents a valuable advancement for precise optical system characterization and correction.