Ku. Kasemir et K. Betzler, Characterization of photorefractive materials by spontaneous noncolinear frequency doubling, APP PHYS B, 68(5), 1999, pp. 763-766
'Spontaneous' noncolinear frequency doubling (SNCFD) is a type of optical s
econd-harmonic generation (SHG) that uses scattered light to provide additi
onal fundamental beams in order to accomplish noncolinear phase matching. B
ased on a novel algorithm for the automated evaluation of the resulting rin
g patterns, we present an easy-to-apply, sensitive, and non-destructive met
hod for the characterization of photorefractive materials, yielding two-dim
ensional spatial resolution. As applications of the technique, examples for
the characterization of lithium niobate crystals are presented.