Branch point agnostic full optical field reconstruction using Shack-Hartmann data.

Area of Science:

• Optical physics
• Adaptive optics
• Wavefront sensing

Background:

• Traditional wavefront reconstruction algorithms struggle with branch point singularities in phase gradients, especially under strong scintillation.
• These branch points are not true singularities but zeros of the optical field, indicating a solvable problem.

Purpose of the Study:

• To develop a robust wavefront sensing method that circumvents branch point issues by reconstructing the full complex optical field.
• To provide an efficient and implementable solution for real-time adaptive optics applications.

Main Methods:

• Reconstructing the full complex optical field using intensity and gradient data from a Shack-Hartmann wavefront sensor.
• Formulating the reconstruction as a linear least-squares problem for the optical field, rather than just the phase.
• Utilizing standard efficient techniques for solving the linear least-squares problem.

Main Results:

• The proposed method accurately reconstructs the full optical field, effectively handling branch points.
• Numerical simulations demonstrate the algorithm's accuracy and robustness to noise in highly scintillated fields.
• The algorithm is efficient and suitable for real-time adaptive optics.

Conclusions:

• Reconstructing the full complex optical field offers a well-posed solution to branch point problems in wavefront sensing.
• This approach enhances the performance of adaptive optics systems, particularly in environments with significant optical turbulence.
• The developed algorithm provides a practical and efficient tool for advanced optical wavefront analysis.