Demonstration of 20-Gbit/s high-speed Bessel beam encoding/decoding link with adaptive turbulence compensation

Area of Science:

• Optical Communications
• Free-Space Optics
• Adaptive Optics

Background:

• Atmospheric turbulence significantly degrades free-space optical (FSO) communication performance.
• Traditional Bessel beam modulation is limited by the slow response of spatial light modulators (SLMs).

Purpose of the Study:

• To propose and experimentally demonstrate a high-speed Bessel beam encoding/decoding FSO link.
• To overcome the speed limitations of SLMs by employing a novel modulation approach.
• To mitigate atmospheric turbulence effects using adaptive optics.

Main Methods:

• Mapping traditional amplitude modulation to spatial modulation for Bessel beam encoding.
• Utilizing an intensity modulator for high-speed modulation, independent of SLM switching speed.
• Emulating atmospheric turbulence using an SLM with a pseudorandom phase mask.
• Implementing an adaptive optics closed loop to compensate for phase distortions.

Main Results:

• Successful demonstration of a 20-Gbit/s Bessel beam encoding/decoding FSO link.
• Achieved high-speed data transmission unaffected by emulated atmospheric turbulence.
• Adaptive optics effectively compensated for phase distortions, ensuring favorable link performance.

Conclusions:

• The proposed method enables high-speed FSO communication through atmospheric turbulence.
• The Bessel beam encoding/decoding speed is determined by the intensity modulator's rate, achieving tens of gigabits per second.
• Adaptive optics compensation is crucial for maintaining link performance in turbulent environments.