Interest in SiC nanopowders has been growing due to the possibilities for u
sing their nonlinear optical properties. The objective of the present work
was to investigate these properties through PISHG (photoinduced second harm
onic generation) and photo transparency measurements. The relation between
structural parameters, such as hexagonality, and external forcing signals,
such as pressure, PISHG, and photo transparency, was established. The high
sensitivity of SHG to pressure suggests that the material investigated may
be suitable for application in contactless pressure measurements.