Experimental studies on the core-structure dependence of backward Brillouin gain in solid-core photonic crystal fibers

Despite many theoretical studies based on either simplified models or numerical simulations, the structural dependency of Brillouin gain spectra in small-core PCFs has not been characterized comprehensively using PCFs with elaborated parameter controls.

In this work we report a comprehensive characterization on the core-structure dependences of backward SBS effects in solid-core PCFs that are drawn with systematically varied core-diameter, revealing several key trends of the fiber Brillouin spectrum in terms of its gain magnitude, Brillouin shift and multi-peak structure, which have not been reported in detail previously. Our work provides some practical guidance on PCF design for potential applications like Brillouin fiber lasers and Brillouin fiber sensing.