Third-order optical measurements of porphyrin compounds using Dark-field and D4σ-Z scan imaging techniques

Abstract

The newly introduced imaging techniques D4 and Dark-field Z-scan (DFZ-scan) are very much appropriate to measure the thirdorder nonlinear (NL) refractive index in the presence of high nonlinear absorption (NLA) in condensed matter. To demonstrate the large potential of both techniques we prepared and characterized porphyrins solutions in chlorobenzene and report here on the NL optical properties

Synthesis, characterization and third-order nonlinear optical properties of a dodecaruthenium organometallic dendrimer with a zinc(ii) tetraphenylporphyrin core

“…Such a situation calls for caution in interpretation of the data, since any 2PA might be convoluted with excited-state absorption phenomena, such as saturable absorption (SA) or reverse saturable absorption (RSA). 28 Positive values are found for 5 2 at 630 nm whereas negative values have been previously found for 4-H, but these differences might be due to the slightly different acquisition conditions and laser pulses used. 38,± More importantly, 2PA is clearly enhanced above 800 nm for 5 2 compared to 4-H and 7, an improvement that might again be attributed to the extended π-manifold of the former compound.…”

“…[Ru] [Ru] Independently from these investigations, large metallated π-architectures such as porphyrins and phthalocyanines were also identified as efficient and robust cubic NLO-phores. [28][29][30][31][32][33] Molecular materials based on these structures were therefore developed and used in various devices, such as optical gates 34 or optical limiters, 32,[35][36] for example. An attractive feature is that peripheral (meso) electron-releasing substituents on the macrocyclic core were shown to enhance the cubic NLO performance at 532 nm.…”

“…Note that no third-order NLO activity was detected for ZnTPP at 1024 nm using dark field Z-scan (DFZ-scan) by Boudebs et al 28 Further, a huge increase is noted for 5 2 and 7 when compared to the 2PA cross-sections reported for the model alkynyl-metal complexes 13 (310 ± 50 GM) and 14 (110 ± 50 GM) at 800 nm, 17,60 a wavelength which nearly corresponds to 2PA in the MLCT state for all these compounds (i.e., nearly twice the wavelength of the MLCT band). Also, 5 2 shows twice the 2PA merit of dendrimer 3 (Chart 1) at 750 nm (σ 2 = 11600 GM).…”

Nonlinear optical properties of meso-Tetra(fluorenyl)porphyrins peripherally functionalized with one to four ruthenium alkynyl substituents

“…45 As a result, purely organic porphyrin-based arrays exhibiting 2PA above 1000 nm remain rare. 44 Thus, no such third-order NLO activity was previously detected for ZnTPP at 1024 nm by Boudebs et al using dark field Z-scan (DFZ-scan), 43 revealing the beneficial influence of metalation by [trans-RuCl(dppe) 2 (C≡C)]-endgroups for promoting nonlinear absorption in the near-IR range. Furthermore, we clearly show here with 5a-5d that increasing the level of "ruthenation" at the periphery correlates with an increase in the effective crosssections of the various maxima detected.…”

“…There is significant linear absorption in this specific spectral range, resulting in excited-state absorption (ESA) as well as two-photon absorption (2PA) and so the 2PA in this spectral range is convoluted with ESA (saturable absorption (SA) or reverse saturable absorption (RSA)), complicating the interpretation of these data. 43 We have therefore not focused on data corresponding to wavelengths below 800 nm and have restricted our analysis to the longer wavelength range where there is no/minimal linear absorption. The compounds also display several nonlinear absorption maxima at longer wavelengths, beyond the 1PA region, in particular at 850-875 nm and 930-950 nm.…”