Physics of the fundamental limits of nonlinear optics: a theoretical perspective [Invited]

Abstract

The theory of the fundamental limits (TFL) of nonlinear optics is a powerful tool for experimentalists seeking to create molecules and materials with large responses, and for theorists who are seeking to understand how the basic elements of quantum theory delineate the boundaries within which these searches should be conducted. On a practical level, the TFL provides a metric for measuring the performance or 'goodness' of new molecules, relative to what is possible. Explorations of large sets of structures within the theory provide insight into new design rules for creating more active molecules. This article is a review of the TFL, starting with a history of its development and its first use to discover that all molecules as of the year 2000 fell a factor of 30 below the limits, and continuing to the present day where the theory continues to provide research opportunities and challenges. The review focuses on off-resonant nonlinear optics in order to sharply focus on the key elements of the TFL, but pointers are provided to the literature for near-and on-resonance applications.

An Insightful Picture of Nonlinear Photonics in 2D Materials and their Applications: Recent Advances and Future Prospects

“…Reproduced with permission. [ 387 ] Copyright 2018, Royal Society of Chemistry.…”

“…NLO theory remains well recognized as well as studied recently in the literature. [ 387 ] Optical limiting tools act significantly for shielding optical detectors and human eyes as of harmful light sources. [ 388 ] In the optical limiting method the light intensity transferred over optical material falls with increasing excitation light fluence away from the definite threshold value.…”

Features of third-order optical nonlinearity in carbon disulfid

“…The molecule dipole optical transition moments cannot be presented as simple analytical expressions for a further analysis and can only be numerically evaluated using computer-based calculations, e.g., by applying molecular calculus [3] or Monte-Carlo approaches [4]. This gap between practical aspects and the theory limits further practical objectives of nonlinear optics, e.g., to synthesize a substance with considerably large nonlinear optical numbers [5]. From this viewpoint, all recent studies of carbon disulfide have one objective in common -to study further the optical nonlinearity fundamentals.…”

General solution to nonlinear optical quantum graphs using Dalgarno–Lewis summation techniques

“…Quantum graphs were recently introduced as general models to explore the fundamental limits of nonlinear optics and to discover the topological and geometrical properties of structures that maximize the nonlinear optical response [1][2][3][4][5]. Like other Hamiltonian models, quantum graphs with specific shapes and topologies have nonlinear optical response near the fundamental limits [6].…”