Orbital-angular-momentum-multiplexed free-space optical communication link using transmitter lenses

Area of Science:

• Optics
• Telecommunications
• Optical Engineering

Background:

• Free-space optical (FSO) communication links offer high bandwidth potential.
• Orbital angular momentum (OAM) multiplexing is an advanced technique to increase FSO capacity.
• Transmitter optics play a crucial role in beam quality and propagation efficiency.

Purpose of the Study:

• To investigate the impact of transmitter lenses on OAM-multiplexed FSO communication systems.
• To evaluate the benefits and drawbacks of employing lenses for focusing OAM beams.
• To assess the influence of lenses on system performance metrics like power loss and error tolerance.

Main Methods:

• Simulations were conducted to model OAM beam propagation with transmitter lenses.
• Experimental setups were used to validate simulation findings in a practical FSO link.
• Power loss, angular error tolerance, and lateral displacement tolerance were analyzed.

Main Results:

• Transmitter lenses can reduce power loss in OAM-based FSO links within specific distances.
• The power loss reduction is more pronounced for higher-order OAM beams.
• System tolerance to angular misalignment is enhanced, while tolerance to lateral displacement is reduced.

Conclusions:

• Transmitter lenses are a viable tool for optimizing OAM-FSO links by mitigating power loss and improving angular stability.
• Careful consideration of potential trade-offs, particularly concerning lateral displacement sensitivity, is necessary for practical implementation.
• Further research may explore adaptive optics or hybrid approaches to overcome lens limitations.