Optical third-harmonic generation in layered perovskite-type material (C10H21NH3)2PbI4

Optical third-harmonic generation has been investigated over a wide range of wavelengths on a layered perovskite-type material (C10H21NH3)2PbI4, which exhibits prominent two-dimensional exciton effects due to the “natural superlattice” structure. The measured nonlinear optical susceptibility χ(3)(−3ω, ω, ω, ω) shows large three-photon resonance to the lowest-energy exciton for the fundamental wavelength at 1.53 μm. The magnitude of χ(3) reaches 10−9 esu, which is comparable to the largest reported value on organic materials with one-dimensional conjugated π-electron structures.