Applying universal scaling laws to identify the best molecular design paradigms for second-order nonlinear optics

Abstract

We apply scaling and the theory of the fundamental limits of the second-order molecular susceptibility to identify material classes with ultralarge nonlinear-optical response. Size effects are removed by normalizing all nonlinearities to get intrinsic values so that the scaling behavior of a series of molecular homologues can be determined. Several new figures of merit are proposed that quantify the desirable properties for molecules that can be designed by adding a sequence of repeat units, and used in the assessment of the data. Three molecular classes are found. They are characterized by sub-scaling, nominal scaling, or super-scaling. Super-scaling homologues most efficiently take advantage of increased size. We apply our approach to data currently available in the literature to identify the best super-scaling molecular paradigms with the aim of identifying desirable traits of new materials.

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

“…In April of this year, two preprints appeared which analyze classes of molecules according to their universal scaling properties, one paper each for β [78] and γ [79]. The authors' stated objective was to identify classes of molecules with superior scaling properties as they increased in size.…”

Topological control of the nonlinear-optical response of hybrid quantum systems

“…[15][16][17] Specifically, focus has been placed on finding molecular units whose (hyper)polarizabilities scale most favorably with the spatial extent of the ground state wave-function, and then utilizing molecular synthesis and engineering to scale up to larger materials. [18][19][20] An ultralarge nonlinear response obtained by such means would mitigate the need for highly intense beams in all-optical switches, as well as enhance the myriad other applicable phenomena in nonlinear optics such as second harmonic generation, third harmonic generation, and the optical Kerr effect.…”