Facile Growth of an Ultraviolet Hydroisocyanurate Crystal with Strong Nonlinearity and a Wide Phase-Matching Region from π-Conjugated (HC3N3O3)2- Groups.

Abstract

Mixed-alkali-metal hydroisocyanurate nonlinear-optical crystal RbLi(HC3N3O3)·2H2O was grown by a facile aqueous solution method. It exhibits a short phase-matching wavelength (λPM = 239 nm) and a strong second-harmonic-generation response (deff = 2.1KDP) benefitting from the well-aligned planar π-conjugated (HC3N3O3)2- anions, as confirmed by the first-principles calculations. Moreover, solar blind ultraviolet radiation can be reached using the title crystal via a fourth-harmonic-generation technique of a Nd-based laser, i.e., 1064 nm/4 = 266 nm.