Electron-Beam Domain Patterning on the Nonpolar Surfaces of LiNbO3 Crystals and in Optical Waveguides Formed on the Nonpolar Surfaces

In this review our recent results on the electron-beam domain writing (EBDW) on the nonpolar surfaces of LiNbO3 crystals of different compositions are presented. The obtained results permitted us to relate the main characteristics of domain formation (the domain sizes and velocity Vf of the frontal motion) to the irradiation conditions (the accelerating voltage U of scanning electron microscopy, EB-current I, the inserted charge Q). The domain depth Td is controlled by U via the electron penetration depth; the domain length Ld increases linearly with Q owing to the domain frontal growth by the viscous friction law. In optical waveguides, the matching of the Td value with the waveguide thickness D provides optimal values of the waveguide conversion to the second harmonic