Transmission of LG Modes in High-Capacity 16 × 10 Gbps FSO System Using FBG Sensors Under Different Channel Scenarios

Area of Science:

• Optical Wireless Communication
• Sensing Technologies

Background:

• Free Space Optics (FSO) offers a reliable, flexible, and cost-effective communication channel.
• Mode-Division Multiplexing (MDM) is a key technique for enhancing transmission capacity in optical links.
• Integrating sensing capabilities into communication systems presents opportunities for novel applications.

Purpose of the Study:

• To propose and evaluate a 16 × 10 Gbps MDM-FSO system that enables simultaneous communication and sensing.
• To investigate the system's performance in transmitting distinct Laguerre-Gaussian (LG) beams over extended ranges (1000-1900 m).
• To assess the impact of varying sensor temperatures and atmospheric conditions on system performance.

Main Methods:

• Implementation of a 16 × 10 Gbps MDM-FSO system utilizing distinct Laguerre-Gaussian (LG) beams.
• Integration of Fiber Bragg Grating (FBG) sensors for temperature monitoring and sensing.
• Transmission experiments conducted over ranges of 1000-1900 m under diverse weather conditions (clear air, drizzle, moderate haze).
• Performance analysis using gamma-gamma and log-normal distribution models to evaluate turbulence effects.

Main Results:

• Successful transmission of higher-order LG beams with FBG sensors at temperatures ranging from 20-120 °C over a 1500 m FSO link.
• Demonstrated robust performance across clear air, drizzle, and moderate haze conditions.
• Gamma-gamma distribution model showed improved performance over log-normal for index modulation under weak-to-strong turbulence.
• Achieved a high optical signal-to-noise ratio (OSNR) of 113.39 dB and a gain of 15.43 dB at an aggregate data rate of 160 Gbps.

Conclusions:

• The proposed MDM-FSO system effectively integrates communication and sensing functionalities.
• The system demonstrates high performance and reliability under various atmospheric conditions and turbulence levels.
• This technology offers a promising solution for advanced optical wireless communication systems with integrated sensing capabilities.