Slow light on Gbit/s differential-phase-shift-keying signals.

Area of Science:

• Optics and Photonics
• Optical Communications
• Nonlinear Optics

Background:

• Optical signal processing is crucial for high-speed communication systems.
• Stimulated Brillouin scattering (SBS) offers a promising avenue for achieving slow light in optical fibers.
• Data-pattern dependence in slow light can degrade signal quality.

Purpose of the Study:

• To demonstrate and analyze the slowing down of phase-modulated optical signals using SBS-based slow light.
• To investigate the impact of slow-light-induced data-pattern dependence on signal demodulation.
• To optimize the slow light system for improved signal quality and robustness.

Main Methods:

• Simulations and experimental setups were employed to study SBS-based slow light.
• A 10.7-Gb/s non-return-to-zero differential phase-shift keying (NRZ-DPSK) signal was used.
• The SBS gain profile was detuned to analyze and mitigate pattern dependence.

Main Results:

• A delay of up to 42 ps was achieved for the NRZ-DPSK signal with error-free performance.
• Analysis revealed the impact of slow light on both constructive and destructive demodulated ports.
• Detuning the SBS gain profile resulted in a 3-dB Q-factor improvement by reducing pattern dependence.

Conclusions:

• SBS-based slow light can effectively delay phase-modulated optical signals.
• Signal performance is sensitive to slow-light-induced pattern dependence, which is modulation format dependent.
• Optimizing SBS gain profiles can enhance the robustness and quality of slow-light systems for optical communications.