100 Gbps Data Transmission Based on Different l-valued OAM Beam Multiplexing Employing WDM Techniques and Free Space Optics

The helical phase front of the light beam carry orbital angular momentum (OAM) with azimuthally phase dependence. OAM beams of different topological charges are generated using spatial laser sources and vortex lens. A wavelength division multiplexing (WDM) based architecture employing different l-valued OAM beams having different modes and wavelengths to realize 100Gbps data transmission over free space is proposed and successfully demonstrated. 10X10 Gbps data-rate is fruitfully transmitted over 3200 m free space and tested for different environmental scenario such as clear weather, haze, rain and fog. A very low bit error rate value of 5 × 10−9, good Q-value of 5.4 with excellent eye-diagram are achieved. This proposed configuration with power penalty of 2.4 dB, which evidenced that the architecture is suitable for free space data transmission. The transmission performance is also enhanced due to sufficiently low crosstalk (~ −25 dB) compared to WDM technique without employing OAM beams.