New devices produce and detect twisted light

If confirmed, this could be a major breakthrough in communications technology!

"Their technique relies on controlling the orbital angular momentum (OAM) of light using a chip-based microlaser. In a separate paper, they also demonstrate, for the first time, that they can detect the OAM of this “twisted” light electronically. The two papers together mark a significant step towards OAM multiplexing in fibre-optic communications and could also have implications for quantum communication."

New devices produce and detect twisted light – Physics World


Tunable topological charge vortex microlaser The orbital angular momentum (OAM) intrinsically carried by vortex light beams holds a promise for multidimensional high-capacity data multiplexing, meeting the ever-increasing demands for information. Development of a dynamically tunable OAM light source is a critical step in the realization of OAM modulation and multiplexing. By harnessing the properties of total momentum conservation, spin-orbit interaction, and optical non-Hermitian symmetry breaking, we demonstrate an OAM-tunable vortex microlaser, providing chiral light states of variable topological charges at a single telecommunication wavelength.

Photocurrent detection of the orbital angular momentum of light However, direct photocurrent detection of different OAM modes has not yet been demonstrated. ... In this study, we designed a photodetector based on tungsten ditelluride (WTe2) with carefully fabricated electrode geometries to facilitate direct characterization of the topological charge of OAM of light. This orbital photogalvanic effect, driven by the helical phase gradient, is distinguished by a current winding around the optical beam axis with a magnitude proportional to its quantized OAM mode number. Our study provides a route to develop on-chip detection of optical OAM modes, which can enable the development of next-generation photonic circuits.