A Comprehensive Review of Nonlinear Optics: Fundamentals, Materials, Devices, and Applications

Abstract

Nonlinear optics has evolved from bulk, high-field laboratory experiments into a practical basis for integrated photonic devices. This review connects the underlying second-order (𝜒² ) and third-order (𝜒³) responses with the engineering constraints that govern chip-scale performance. It compares thin-film lithium niobate, silicon nitride, III–V semiconductors, chalcogenide glasses, epsilon-near-zero (ENZ) oxides, and nonlinear metasurfaces using a system-level framework rather than the nonlinear coefficient alone. Across these platforms, propagation loss, phase matching, dispersion, thermal drift, fabrication tolerance, coupling, and packaging often determine usable conversion efficiency more strongly than an isolated material parameter. Thin-film lithium niobate is especially effective for 𝜒² conversion and electro-optic control; silicon nitride supports low-loss, high-Q Kerr combs; III–V materials provide strong confinement and compact interaction lengths; and ENZ structures and metasurfaces exploit local-field enhancement in ultrathin geometries. The review also evaluates measurement and reporting practices, fabrication-aware inverse design, programmable nonlinear interactions, and reliability requirements. No platform is universally superior: the appropriate choice depends on application-specific demands for efficiency, bandwidth, noise, tunability, footprint, and manufacturability. Future progress will require consistent bench-marking, uncertainty-aware optimization, wafer-scale process control, and packaging strategies that preserve laboratory performance in deployable systems.

Received: 26 March 2026 | Revised: 2 July 2026 | Accepted: 19 August 2026

Conflicts of Interest

The authors declare that they have no conflicts of interest to this work.

Data Availability Statement

Data sharing is not applicable to this article as no new data were created or analyzed in this study.

Author Contribution Statement

Raneen Salam: Conceptualization, Methodology, Investigation, Data curation, Writing – original draft, Writing – review & editing, Visualization. Haneen Abass Alrubaie: Conceptualization, Methodology, Validation, Writing – original draft, Writing – review & editing, Supervision, Project administration. Ghasaq A. Tomaa: Validation, Investigation, Writing – review & editing. Samah A. Al-Heeti: Investigation, Data curation, Writing – review & editing, Visualization.