Abstract
A subwavelength‐thick spatial‐mode multiplexer based on a highly transparent all‐dielectric Mie‐resonant metasurface is demonstrated with a broadband response covering major optical communication wavelength bands. The metasurface is employed to convert simultaneously each orthogonal polarization of LP01 inputs into individual higher‐order TM01 and TE01 vectorial modes, without the need of a polarization diversity setup. This is not feasible using current mode multiplexing approaches. An LP01 polarization‐multiplexed 51 × 64 quadrature amplitude modulation (QAM) superchannel, with a 10.3 bits s−1 Hz−1 spectral‐efficiency and total bit‐rate of 13.2 Tb s−1, is converted to higher‐order modes with the metasurface multiplexer, and then mode‐multiplexed data is transmitted over a multimode fiber. The results demonstrate the potential application of these metadevice‐based mode multiplexers in space‐division multiplexed systems.
