Nonlinear optical properties of organic and polymeric materials
29 Sep 1983-
About: The article was published on 1983-09-29 and is currently open access. It has received 762 citations till now.
Citations
More filters
TL;DR: In this paper, the Hartree-Fock level linear and nonlinear static electronic polarizabilities of trans-polysilane polysilane (t−PSi) were obtained at Hartree level by extrapolation of ab initio calculations on the oligomers H3Si−(SiH2)N−SiH3 (N odd) for the longitudinal components, in particular, a 6-31 G basis is shown to yield accurate values if the chains are long enough.
Abstract: Linear and nonlinear static electronic polarizabilities of the σ‐conjugated polymer trans‐polysilane (t‐PSi) are obtained at the Hartree–Fock level by extrapolation of ab initio calculations on the oligomers H3Si–(SiH2)N–SiH3 (N odd). For the longitudinal components, in particular, a 6–31 G basis is shown to yield accurate values if the chains are long enough. No computational advantage is found in using effective core potentials. Chain lengths through N=13 are sufficient to give limiting infinite chain polarizabilities with relatively small uncertainty. The calculated longitudinal linear polarizability per SiH unit is about the same as the corresponding property in the prototype π‐conjugated polymers polyacetylene (PA) and polydiacetylene (PDA), but the longitudinal second hyperpolarizability is significantly less in the σ‐conjugated polymer. In t‐PSi the conjugation length is about half that in either PA or PDA. Frequency‐dependent vibrational distortion contributions are estimated in the doubly harmoni...
86 citations
TL;DR: The third-order optical susceptibilities of VOPcandTiOPc were determined by optical third-harmonic generation (THG) measurements atwavelengths 1543 nmand 1907 nm as mentioned in this paper.
Abstract: The third-order optical susceptibilities χ1111(3)(-3ω; ω, ω, ω)sfortwodifferentphasesinvanadylandtitanylphthalocyanine (VOPcandTiOPc) vacuum-depositedthinfilmsaredeterminedbyopticalthird-harmonicgeneration (THG) measurementsatwavelengths 1543 nmand 1907 nm. Thermalannealingcausesaphasetransitionwhichaccompaniesaredshiftintheirabsorptionspectraandanincreaseinthe χ^(3) valueof 2-5 timesinVOPcandTiOPcfilms. Theenhancementofthethird-orderopticalnonlinearitiesintetravalentphthalocyaninefilmsisdiscussedintermsofmolecularpacking.
84 citations
TL;DR: In this paper, the authors derived equations of motion for the single electron reduced density matrix, and solved them using the time dependent Hartree-Fock (TDHF) approximation, and further mapped the system onto a set of coupled harmonic oscillators.
Abstract: Molecular optical susceptibilities are calculated by deriving equations of motion for the single electron reduced density matrix, and solving them using the time dependent Hartree–Fock (TDHF) approximation. The present approach focuses directly on the dynamics of the charges in real space and completely avoids the tedious summations over molecular eigenstates. It further maps the system onto a set of coupled harmonic oscillators. The density matrix clearly shows the electronic structures induced by the external field, and how they contribute to the optical response. The method is applied to calculating the frequency‐dispersed optical susceptibility χ(3) of conjugated linear polyenes, starting with the Pariser–Parr–Pople (PPP) model. Charge density wave (CDW) like fluctuations and soliton pair like local bond‐order fluctuations are shown to play important roles in the optical response of these systems.
83 citations
TL;DR: The observation of optical phase conjugation utilizing the intrinsic Kerr-like nonlinear susceptibilities of two soluble polydiacetylenes was reported in this article, where the reflectivities of up to 40% were observed on a timescale of ≲100 ps and a value of χ(3)xyyx =7×10−12 esu evaluated.
Abstract: The observation of optical phase conjugation utilizing the intrinsic Kerr‐like nonlinear susceptibilities of two soluble polydiacetylenes is reported. Phase conjugate reflectivities of up to 40% were observed on a timescale of ≲100 ps and a value of χ(3)xyyx =7×10−12 esu evaluated.
82 citations