Demonstration of a 280  Gbit/s free-space space-division-multiplexing communications link utilizing plane-wave...

Area of Science:

• Optical Communications
• Free-Space Optics
• Photonics

Background:

• Free-space optical communication systems offer high bandwidth potential.
• Space-division multiplexing (SDM) enables increased data capacity by transmitting signals through independent spatial channels.
• Efficient generation and control of multiple spatial channels are crucial for advancing SDM systems.

Purpose of the Study:

• To demonstrate a high-capacity free-space space-division multiplexing (SDM) communication link.
• To investigate the use of tilted truncated plane-waves for spatial channel generation.
• To evaluate the performance of the developed SDM link in terms of data rate, crosstalk, and bit-error rate.

Main Methods:

• A free-space communication link was established using two identical linear fiber-arrays separated by approximately 5 meters.
• Each fiber array was positioned at the back-focal plane of a spherical lens, creating conjugate image planes.
• Seven independent tilted truncated plane-wave channels were generated, each carrying a 40 Gbit/s 16-QAM signal.

Main Results:

• A total data transmission rate of 280 Gbit/s was achieved.
• Channel crosstalk was maintained below 26 dB.
• The bit-error rate (BER) remained below the forward error correction (FEC) threshold of 3.8×10⁻³.

Conclusions:

• The study successfully demonstrated a high-capacity free-space SDM communication link.
• The proposed method effectively generates and utilizes multiple spatial channels for high-speed optical communication.
• The achieved performance metrics indicate the viability of this approach for future optical networks.