  Vector field measurement is demonstrated with an all-optical scalar atomic
magnetometer using intrinsic parameters related to its scalar operation. The
Bell-Bloom type atomic magnetometer measures the Larmor precession of cesium
atoms through on-resonant absorption of a probe beam. While the AC component of
the probe signal is used for the field magnitude measurement, the probe DC
signal contains information about the polar angle, defined as the angle between
the magnetic field and the probe beam. Additional polar angle information is
obtained from the light-shift-induced magnetic field caused by the frequency
modulation of the probe beam. With a measurement time of 100 milliseconds,
better than 0.02 degree sensitivity has been achieved using a commercial
miniaturized sensor at the optimal sensor orientation. The angle measurement
accuracy is checked against an optical encoder over the entire polar angle
range of 0 to 180 degrees. Better than 1 degree error is recorded over most set
polar angles. Azimuthal angle measurement is also exhibited with two
orthogonally oriented sensors.
