Generation of 200 OAM channels for 10 Tbps free space data transmission using POLMUX based WDM and self-injection locked QD-LD

Orbital angular momentum (OAM) beams, containing helical phase structures are extensively used as data carriers due to their additional degree of freedom. OAM beam containing different modes with different l -values are always mutually orthogonal to each other. The orthogonal property of the OAM-modes reduces the intermodal crosstalk. A 10 Tbps free-space data transmission system enabled with self-injection locked quantum dash-laser diode (QDLD) and successive multiplexing of different wavelengths, OAM modes, and polarisation states of light-wave are proposed and analysed using simulation. Self-injection locked QDLD is used to generate 10 optical carriers, which results in significant reduction in cost and complexity of the system. Combination of wavelength division multiplexing, OAM multiplexing, polarisation multiplexing enhances the number of data channels up to 200. The parallel generation and detection of OAM modes have been performed employing Dammann optical vortex gratings. (10 × 10 × 2 × 50) Gbps data has been successfully transmitted over a 10 m free-space optics link. Open eye and clear constellation diagrams with a very low power penalty of 2.1 dB at a bit-error-rate value of 2.2 × 10 –3 have been achieved in our proposed architecture, which authenticates the feasibility of the system.