High-speed wavefront reconstruction of a Gaussian beam propagating through controlled optical turbulence

Any beam that propagates through optical turbulence will experience distortions in both its amplitude and phase, leading to various effects such as beam wandering, beam spreading, and irradiance fluctuations. Reconstructing the complete field of a perturbed beam is a challenging task due to the dynamic nature of these effects. Interferometric wavefront reconstruction techniques—such as those based on holography—are commonly used but are hindered by their sensitivity to environmental disturbances and alignment errors. However, new complex phase retrieval methods based on propagation equations have emerged, which do not require prior knowledge of the beam to be reconstructed and are suitable for amplitude or phase objects, or both. We propose an experimental implementation of a complex phase retrieval technique for characterizing Gaussian beams propagating through optical turbulence, using binary amplitude modulation with a digital micro-mirror device (DMD). This approach is ideal for dynamic applications and has enabled us to achieve experimental high-speed complex wavefront reconstruction of optical beams through controlled real turbulence. This experiment corresponds to the initial step in our research focused on gaining a deeper understanding of optical turbulence from an experimental perspective.