Recently, the state-of-the-art of lithium-niobate-on-insulator (LNOI) has been reviewed [1]. In analogy to silicon-on-insulator (SOI), the new material platform for integrated optics with wafers of up to 3' diameter enables the fabrication of optical waveguides with small cross-sections and small bending radii due to the high refractive index contrast. As a consequence, ultra-compact photonic integrated devices such as ring resonators and photonic crystal structures have been developed. © 2013 IEEE.