Stimulated Brillouin Review: Invented 50 Years Ago and Applied Today

Figure 2

Fabry-Perot interferogram from Q-switched ruby laser (left) and from SBS in nitrobenzene (right). After the first order Stokes ring, additional rings are attributed to phase conjugation returning the Stokes light to the laser where it experiences additional gain in the inhomogeneously broadened ruby laser [adapted from [4]].