Processing Entangled Photons in High Dimensions with a Programmable Light Converter

High-dimensional entanglement offers a variety of advantages for both fundamental and applied applications in quantum information science. A central building block such is programmable processor entangled states, which crucial the certification, manipulation, distribution high-dimensional entanglement. The leading technology processing photons integrated multiport interferometers. However, devices are incompatible with structured light their scaling challenging. Here, we unlock these limitations by demonstrating reconfigurable high dimensions that based on multiplane conversion (MPLC), has recently been developed multiplexing hundreds spatial modes classical communication. We use our MPLC platform to certify three-dimensional two mutually unbiased bases, perform 400 arbitrary random transformations photons, convert mode basis distribution.