Analysis of the Brillouin gain spectrum in a graded-index multimode fiber

Abstract

We present a numerical method for computing the Brillouin gain spectrum (BGS) in a graded-index multimode fiber (GI-MMF). The BGS is shown to strongly depend on the pump and probe modal content. In particular, the peak frequency of the BGS, usually referred as Brillouin Frequency Shift (BFS), as well the BGS bandwidth, vary dramatically with the order of the optical modes interacting along the fiber.