Nonlinear optical characterization in a generalized Fibonacci-type optical
superlattice, which can be generated by the concurrent inflation rule A -->
A(m)B and B --> A (where m=positive integer), has been studied both theore
tically and experimentally. Quasi-phase-matched second-harmonicgeneration s
pectrum and direct third-harmonic-generation with high efficiency have been
measured in a LiTaO3 superlattice structure with m=2. Two different struct
ures in real space have shown a similarity in reciprocal space. (C) 1999 Am
erican Institute of Physics. [S0003-6951(99)02430-4].