Harnessing Quasi-Wavelet Conformal Mapping Microstructures for High-Performance Twisted Light Demultiplexing

Space-division multiplexing (SDM) has emerged as a promising technology for both classical and quantum communications. Twisted light, particularly in the form of orthogonal optical vortex beams, offers significant potential for SDM by enhancing the capacity and performance of optical communication systems. A critical component in such systems is a twisted light (de)multiplexer, which enables scalable and efficient (de)multiplexing of twisted light to meet the demands of high-capacity optical communications. In this work, we propose and experimentally demonstrate quasi-wavelet conformal mapping microstructures for efficient twisted light demultiplexing. These microstructures, specifically designed and fabricated for this experiment, successfully demultiplex 11 optical vortex beams with a low crosstalk below −20.9 dB at the target wavelength. Moreover, the microstructures exhibit a broad operational bandwidth (1525–1570 nm), maintaining crosstalk levels under −13 dB. To further validate their performance, the microstructures are also tested in the demultiplexing of various configurations of multiplexed two-channel optical vortex beams. The presented quasi-wavelet conformal mapping microstructures with compact size and exceptional demultiplexing performance hold great promise for applications in high-capacity optical communication systems using twisted light.