  A passive white light cavity (WLC) based on a fiber resonator can be used for
high-bandwidth optical data buffering. Here, we report on experimental studies
of such a WLC, employing stimulated Brillouin scattering (SBS)for producing the
negative dispersion, using two different configurations. In one configuration,
an absorption peak produced by a Brillouin pump is used. In the other
configuration, two gain peaks produced by two separate Brillouin pumps are
employed. In each case, we see evidence of the WLC effect. However, the range
of parameters accessible experimentally limits the degree of the WLC effect
significantly. We present a theoretical analysis for the optimal combinations
of parameters, such as a high Brillouin gain coefficient and a low transmission
loss, necessary for achieving the condition of a vanishing group index, as
required for creating an ideal WLC.
