Measurement of the Brillouin Gain Spectrum of Hollow-Core Photonic Band-Gap Fibers

We have measured the stimulated Brillouin gain spectrum of HC-PBG fibers. The novel highly sensitive measurement scheme is based on two frequency-modulated DFB laser diodes employed as pump-and Stokes sources. The counter-propagating, frequency-modulated pump-and Stokes fields stimulate Brillouin scattering with a frequency-modulated Brillouin shift.