Since the discovery of optical nonlinearities in the 1960s, lithium niobate (LiNbO 3 , or LN) has been the most widely used second-order ( χ (2) ) material, with applications ranging from nonlinear wavelength conversion for classical and quantum light source [1], optical modulators for data communications [2], as well as surface acoustic wave (SAW) based electronic components for mobile phone industry [3]。与其他常见的光子材料相比,LN在非线性和线性光学方面具有许多有利的特性。LN中最大的χ(2)张量分量是对角线对齐的(χ(2)ZZZ),对于非线性波长转换(称为D 33)和电仪调制(r 33),对于非线性波长转换(称为D 33)。作为线性光学材料,LN具有相对较高的普通和非凡的折射率(N O = 2.21,N E = 2.14,在1550 nm处),并且高度