Wavefront reconstruction algorithm for wavefront sensing based on binary aberration modes

Abstract

We propose a new algorithm for wavefront sensing based on binary intensity modulation. The algorithm is based on the fact that a wavefront can be expended with a series of orthogonal and binary functions, the Walsh series. We use a spatial light modulator (SLM) to produce different binary-intensity-modulation patterns which are the simple linear transformation of the Walsh series. The optical fields under different binary-intensity-modulation patterns are detected with a photodiode. The relationships between the incident wavefront modulated with the patterns and their optical fields are built to determinate the coefficients of the Walsh series. More detailed and strict relationship equations are established with the algorithm by adding new modulation patterns according to the properties of the Walsh functions. An exact value can be acquired by solving the equations. Finally, with the help of phase unwrapping and smoothing, the wavefront can be reconstructed. The advantage of the algorithm is providing an analytical solution for the coefficients of the Walsh series to reconstruct the wavefront. The simulation experiments are presented and the effectiveness of the algorithm is demonstrated.

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“…[12][13][14] Then, it is essential to take the influence of turbulent medium into account in designs and applications of free-space optical communication links, and the mitigation of the turbulence effect has aroused considerable interests. Adaptive optics (AO) [15][16][17] is one of the effective methods to alleviating turbulence and the distorted beam profile is measured to derive a sequential error correction pattern, which is then sent through a feedback loop to the beam correction module to compensate for the beam distortion in a typical AO system. In addition, special beams with approximately non-diffracting properties, such as Bessel-Gaussian beams, [18] Hankel-Bessel beams (HB), [19] Airy vortex beams, [20] and Lommel-Gaussian beams, [21] are highly tolerant of turbulence and have been found to offer advantages over diffractive beams.…”

Multiple-image encryption by two-step phase-shifting interferometry and spatial multiplexing of smooth compressed signal

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