  We present experimental studies of nanosecond electric modification of the
order parameter (NEMOP) in a variety of nematic materials with negative
dielectric anisotropy. The study demonstrates that NEMOP enables a large
amplitude of fast (nanoseconds) electro-optic response with the field-induced
birefringence on the order of 0.01 and a figure of merit (FoM) on the order of
$10^4$ $\mu $m$^2/$s; the latter is orders of magnitude higher than the FoM of
the Frederiks effect traditionally used in electro-optic nematic devices. The
amplitude of the NEMOP response is generally stronger in nematics with larger
dielectric anisotropy and with higher natural (field-free) birefringence.
