Flexible terabit/s Nyquist-WDM super-channels using a gain-switched comb source

Area of Science:

• Optical Communications
• Photonics
• Telecommunications Engineering

Background:

• Terabit/s super-channels are essential for next-generation optical networks.
• Optical frequency combs are a promising technology for generating these super-channels.
• Existing methods for comb generation require improvement in stability and flexibility.

Purpose of the Study:

• To demonstrate a stable and flexible method for generating optical frequency combs for terabit/s super-channel transmission.
• To evaluate the performance of these combs in high-speed optical data transmission experiments.
• To achieve high spectral efficiency and net data rates over standard single-mode fiber.

Main Methods:

• Utilizing injection locking of a gain-switched laser diode to generate optical frequency combs.
• Conducting transmission experiments with varying comb line spacings and modulation formats (16QAM, QPSK).
• Transmitting data over standard single-mode fiber (SSMF) up to 300 km.

Main Results:

• Achieved an aggregate line rate of 1.296 Tbit/s (1.109 Tbit/s net) over 150 km SSMF using 9 comb lines and 16QAM.
• Demonstrated a boosted line rate of 2.112 Tbit/s (1.867 Tbit/s net) over 300 km SSMF using QPSK and a wider bandwidth.
• Attained high spectral efficiencies of up to 7.8 bit/s/Hz (6.7 bit/s/Hz net).

Conclusions:

• Injection-locked gain-switched laser diodes provide a stable and flexible platform for terabit/s super-channel generation.
• The demonstrated approach supports high data rates and spectral efficiencies crucial for future optical networks.
• This method offers a viable solution for advancing optical interconnects and high-capacity communication systems.