Proton exchanged samples of LiNbO3 have been profiled by micro-Raman s
pectroscopy, secondary ion mass spectroscopy, Rutherford backscatterin
g channeling, and by x-ray diffraction (XRD). Following proton exchang
e (PE) there are two different phases in addition to pure LiNbO3 detec
ted by XRD. After successive annealing steps the outermost phase disap
pears and an interfacial region forms progressively between PE and LiN
bO3. Specific vibrational bands are correlated to electro-optic and no
nlinear optical properties of the system, and the recovery of these pr
operties upon annealing is correlated to chemical bonding changes.