  We have performed a comparison of laser (LsOPM) and lamp (LpOPM) pumped
cesium vapor magnetometers. Although the LsOPM operated 50% above its
shot-noise limit we found an intrinsic sensitivity of 15 fT/\sqrt{Hz} and 25
fT/\sqrt{Hz} for the LsOPM and LpOPM respectively. Two modes of operation,
viz.,the phase-stabilized and the self-oscillating mode were investigated and
found to yield a similar performance. We have compared the performance of the
LsOPM and the LpOPM directly by simultaneous measurements of field fluctuations
of a 2 microtesla magnetic field inside a multilayer magnetic shield and have
used one of the magnetometers for an active field stabilization. In the
stabilized mode we found a gradient instability of 25 fT within an integration
time of 100 s, which represents an upper limit of the long-term stability of
the magnetometers.
