System Performance Optimization of Frequency-Swept Pump-Based Rectangular Brillouin Optical Filter

• Main Authors: M. Shi, L. Yi, W. Wei, G. Pu, W. Hu
• Format: Article
• Language: English
• Published: IEEE 2017-01-01
• Series: IEEE Photonics Journal
• Subjects: Rectangular optical filter; microwave photonic filter; frequency sweep; stimulated Brillouin scattering (SBS)
• Online Access: https://ieeexplore.ieee.org/document/7782775/

In this paper, we realize a series of 2-GHz wide rectangular optical filters based on the stimulated Brillouin scattering (SBS) effect in optical fiber with a frequency-swept pump and gain feedback compensation scheme. The frequency sweep pump period is a key parameter to achieve acceptable signal performance in the frequency-swept pump based SBS gain filter. We evaluate the system performance of the signal, which is fed into the SBS filter based on frequency-swept pump with different sweep periods ranging from 0.1 to 100 μs, in terms of eye diagrams and bit-error rate (BER) after 12.5 and 25 km of fiber transmission, respectively. Both 500-Mb/s and 1-Gb/s on-off-keying (OOK) signals are used for real-time signal quality evaluation. The optimum eye diagram and BER performance are achieved after 25 km transmission under a 1 μs frequency sweep pump period, as well as after 12.5-km transmission under a 0.5 μs sweep period. The experimental results show that the optimal frequency sweep pump period is always around 1/120 of the signal propagation time in the fiber for different transmission length, providing a guideline on the design of the frequency-swept pump based SBS gain filter and its applications.