Brillouin scattering property in a highly nonlinear photonic crystal fiber (HNL-PCF) with hybrid-core structure is experimentally investigated. The HNL-PCF comprises a highly Ge-doped core surrounded by a triangularly-arranged F-doped buffer. It is experimentally shown that there exist five Brillouin resonance peaks with ~300 MHz frequency spacing in the Brillouin gain spectrum, which can be cl...
