Two‐Photon Absorption and Excited‐State Refractions in Anthraquinone Dyes

Abstract

We examine the nonlinear optical properties of solutions of 9,10‐anthraquinone, 1,4‐dihydroxy‐anthraquinone, 5,8‐dichloro‐1,4‐dihydroxy‐anthraquinone and 1,4‐bisethylamino‐anthraquinone by means of the intensity‐dependent transmission and the Z‐scan method with 532 nm 8 ns pulses. The results demonstrated that the 9,10‐anthraquinone displayed a two‐photon absorption (TPA) character. The molecular TPA cross section of this compound is estimated as σ2 = 7.22 × 10−19 cm4/GW or σ2 = 26.96 × 10−48 cm4/photon/s, respectively, and an essential state of ‘m1Ag’, which should be located near the 2ω virtual transition state, is predicted. On the other hand, the effective excited‐state nonlinear refractive coefficients n2eff of these anthraquinones are found to be ∼10−10 esu, which are comparable with those highly conjugated planar molecules of tetrabenzporphyrins and phthalocyanines.

Linear and nonlinear optical properties of novel Schiff‐base modified calix[4]arene: Synthesis and characterization

“…Tetra-para-tertbutyl-calix [4]arene (compound 1) and debutylated tetra-para-tertbutyl calix [4]arene were synthesized according to the Gutsche procedure. [13,14] 2.1 | Synthesis [4] arene (5,11,17,23-tetra formylcalix [4]…”

“…where x is the normalized distance (x = z/z 0 ) and z 0 is Rayleigh length and Δφ 0 is the phase change. The nonlinear refractive index n 2 is considered as [11] :…”

“…T is the transmittance of light from the cuvette cell. In order to determine the nonlinear absorption, we used the wellknown theoretical formula of [11] :…”

“…In addition, due to the existence of conjugated benzene rings in the Schiff-base compounds, the delocalization of the π-electrons can be extended, and they show higher NLOefficiency in terms of high hyperpolarizability values. [11,12] Based on the evidence described above, in the current work, we report the synthesis of upper rim tetra-arylimino calix [4]arenes from tetrakis-para-formylcalix [4]arene. In this way, the conjugation system is extended and we expect that new functionalized calix [4]arenes show higher NLOefficiency in terms of high hyperpolarizability values.…”

From Light to Structure: Photo Initiators for Radical Two‐Photon Polymerization

“…[70] Twophoton fluorescence dyes with an anthraquinone unit are also known to literature. [71][72][73][74][75][76] Their good chemical modifiability makes them interesting candidates as photo initiators in twophoton polymerization.…”