  The asymmetric magnetization reversal in exchange biased Fe/MnF$_{2}$
involves coherent (Stoner-Wohlfarth) magnetization rotation into an
intermediate, stable state perpendicular to the applied field. We provide here
experimentally tested analytical conditions for the unambiguous observation of
both longitudinal and transverse magnetization components using the
magneto-optical Kerr effect. This provides a fast and powerful probe of
coherent magnetization reversal as well as its chirality. Surprisingly, the
sign and asymmetry of the transverse magnetization component of Fe/MnF$_{2}$
change with the angle between cooling and measurement fields.
