Structured light probe for turbulent media

Atmospheric and oceanic environments are characterized by continuously varying currents, which constantly mix together and form turbulence. As light propagates through turbulence, it experiences distortions from refractive index variations, aberrating the wavefront. This forms a major challenge by degrading free-space optical communications, but also presents a significant opportunity for advanced environmental monitoring as turbulence is driven by environmental conditions. Conventional methods of measuring turbulence, which input a static wavefront and measure the resulting distortion following propagation are fundamentally limited in that they sample only a single row of the transmission matrix. Here, we demonstrate a complementary technique of rapidly structuring a probe beam's wavefront using a silicon photonic integrated circuit and a multi-plane light converter. We experimentally reconstruct single-plane transformations by shaping the amplitude and phase profile of the input wavefront. We achieve a mean accuracy of -1.234dB relative to the theoretical limit for 15 Hermite-Gaussian modes. This proof-of-concept is scalable to more modes and, with future high-speed electro-optical integration, offers a route towards high-fidelity turbulence and weather sensing.