Phys.org December 3, 2024
Light transmission through a multimode fiber (MMF) has gained major importance for imaging and manipulation. Most phase retrieval algorithms used for a MMF implicitly assume light propagation to be described by a unitary operation, yet the transmission matrix of a multimode fiber is inherently non-unitary. An international team of researchers (UK, Australia) demonstrated that this assumption could impede the performance of many commonly used MMF phase retrieval algorithms and demonstrated that the weighted Yang–Gu algorithm outperformed other phase retrieval algorithms in this scenario. Once accounted for, the non-unitary property of the transmission matrix could be leveraged to generate intricate intensity and phase patterns at the output of the fiber, and shape specific output fields. According to the researchers this was experimentally demonstrated by generating Laguerre–Gaussian beams that carry orbital angular momentum, and by forming images in planes offset from the distal end of the fiber facet… read more. TECHNICAL ARTICLE
Experimental projection of Bessel beam, Airy beam and Laguerre-Gauss beams… Credit: University of Adelaide.