Abstract

Lithium niobate (LiNbO₃) is a unique crystal that demonstrates a large range of properties such as photo-refractivity, electro-optical effect and piezoelectricity. Besides, the LiNbO₃ crystal also possesses strong nonlinear optical properties, which are maintained in subwavelength structures such as nanowires. Thus, LiNbO₃ nanowires and microwires are demonstrated to generate and guide the second-harmonic signal [1–4]. The guided second-harmonic signal can be applied for localized imaging [1] and light conversion. However, in order to further develop nanowire-based application, one should also demonstrate other nonlinear optical effects such as sum-frequency generation (SFG). Indeed, nanowires that generate and guide the SFG signal can be applied for all-optical switching and for obtaining unconventional spectral ranges.

© 2017 IEEE