Tunable Orbital Angular Momentum (OAM) Conversion on 100Gb/s Real Data Traffic by Exploiting Concentric Waveguide Emitters

Abstract

We propose an OAM converter exploiting an innovative integrated OAM multiplexer based on concentric omega-shaped waveguides. The OAM converter, which can operate on signals multiplexed both in OAM and wavelength domain, is successfully tested up to 100Gb/s with real data-traffic.

Multiplane Orbital Angular Momentum and Wavelength Switch based on Integrated Tunable Vortex Emitters

“…All M MZM electrical ports on each card are connected to a buffer stage responsible for queueing and routing the packets to the proper MZM according to the destination port. MZM outputs are connected to the M inputs of the OAM modulator/multiplexer (OAM mod+mux, [6]), which converts each of the M signals from Gaussian to an OAM of selectable order, and multiplexes them. The multiplexed OAM beams from the different cards, further multiplexed by means of common free-space beam combiners, propagate in free-space to reach a single OAM demodulator/demultiplexer (OAM demod+demux, realized with two cascaded patterned refractive elements followed by a lens [7]).…”

“…2(a). In order to test the switch in a demanding condition, a 30 Gbaud signal (16QAM) at 1547 nm is generated, amplified and sent to the OAM mod+mux [6], where it is converted from Gaussian to OAM. By changing the controller voltage, the waveguide refraction index in the OAM mod+mux is changed by means of the the thermo-optic effect, thus changing the order of the emitted OAM mode [8].…”