We experimentally demonstrate backward second-harmonic generation in p
eriodically poled LiNbO3 with a 3.3-mu m domain period. We observed hi
gh-order phase matching near 1490, 1600, and 1700 nm (fundamental) for
the 19th, 16th, and 17th orders, respectively, with a maximum convers
ion efficiency of 0.02%. (C) 1997 Optical Society of America.