He-implanted optical waveguides in Y-cut LiNbO3 wafers were studied by
means of conventional high-resolution and grazing incidence X-ray dif
fraction. The depth-resolved strain profiles were derived from the mea
sured rocking curves, depending on the implantation dose. The obtained
results demonstrated the high sensitivity of diffraction techniques t
o the structural modifications in He-implanted LiNbO3 and allowed to s
hed some light on the mechanism of the waveguide formation in damaged
layers.