The limitation to transmission distance of superluminal propagation in the Brillouin fiber ring resonator is investigated.
In this paper, a strategy to achieving long-distance superluminal propagation is proposed and validated by cascading two fiber ring resonators. Nevertheless, the maximum transmission distance of superluminal propagation is basically limited in the Brillouin fiber ring resonator.
Single longitudinal mode (SLM) operation in Brillouin fiber laser is guaranteed by the dozens of meter cavity length corresponding to the bandwidth of natural Brillouin gain. Owing to the perfect self-adaptation and linewidth narrowing effect of lasing Stokes wave in short fiber cavity, the scheme shows strong robustness and inherent stability in achieving Brillouin-induced loss resonance.
Recently, superluminal propagation based on SBS has been demonstrated in Brillouin fiber ring resonator owing to the enhancement of intra-cavity oscillating Stokes power. In the comparison of the above methods, Brillouin-induced slow and fast light offers interest advantages such as moderate pump power threshold, room temperature operation and inherently compatibility with optical communication, as seen in ref. Particularly, slow and fast light has been implemented in optical fiber which makes this technique inherently compatible with optical communication systems. Tremendous approaches have been widely demonstrated by the creation of the sharp spectra resonances based on kinds of nonlinear effect, such as electromagnetically induced transparency (EIT), coherent population oscillation (CPO), stimulated Raman scattering (SRS), stimulated Brillouin scattering (SBS) and cross gain modulation (XGM). In the past few years, the control of the light speed in optical media has attracted much recent research interest due to its interesting potential applications as all-optical variable delay lines, optical signal processing and light-matter interaction enhancement.