Laser-Induced Domain Engineering in Potassium Tantalate Niobate Crystals for Ultra-Broadband Second-Harmonic Generation (Laser Photonics Rev. 20(19)/2026)

Abstract

Ultra-broadband Second-Harmonic Generation

The simultaneous generation of nonlinear Raman-Nath diffraction, Čerenkov-type radiation, and enhanced Bragg diffraction in the femtosecond laser-induced domain structure in a potassium tantalate niobate crystal confirms the fulfillment of quasi-phase matching conditions. Crucially, the structure demonstrates highly efficient second-harmonic generation across an ultra-broad 300-nm wavelength range in the infrared, enabling robust conversion into the visible spectrum. The work by Yuechen Jia, Hongliang Liu and co-workers (see Research Article e71256) establishes laser-induced phase transition engineering as a versatile platform for creating high-performance, multi-functional nonlinear photonic devices, offering a compelling solution for applications in integrated quantum light sources, broadband frequency converters, and advanced optical communications.