Lithium Niobate (LiNbO3) possesses a combination of unique electro-optical, acoustic, piezoelectric, photoelastic and non-linear optical properties with exhibiting mechanical and chemical stability.
Lithium Niobate is strongly birefringent, lacks inversion symmetry and displays Pockels effect. Its birefringence is highly temperature dependent, that's why accurate heating of the crystal can be used to achieve phase matching in the medium. It possesses large effective non-linear, electro-optic and acousto-optic coefficients.
Lithium Niobate is commonly used in electro-optical, acousto-optical and non-linear optical devices, Pockels cells, optical parametric oscillators, optical switches for gigahertz frequencies, high-temperature acoustic transducers, receivers-transmitters of acoustic vibrations, laser frequency doubling, Q-switching devices for lasers.
The transverse modulation is mostly employed for LiNbO3 crystal for using as frequency doubler for wavelength >1 µm and optical parametric oscillator (OPO) pumped at 1064 nm as well as quasi-phase-matched waveguide doublers.