Nonlinear optical behaviour of indium-phthalocyanine tethered to magnetite or silica nanoparticles

Abstract

Nonlinear absorption and optical limiting properties of indium phthalocyanine (complex 1) tethered to magnetite (SiMNP-1) or silica (SiNP-1) nanoparticles have been investigated using 10 ns pulses at 532 nm laser excitation. The optical limiting behaviours of the nanocomposites and the bare phthalocyanine are compared. Investigation of the triplet state dynamics revealed highly efficient triplet state absorption in the SiMNP-1 dyad. A large nonlinear absorption (b eff ) that increased with decrease in the peak input fluence was observed for SiMNP-1. The SiNP-1 composite showed a slight increase in b eff with decreasing peak input fluence. The nonlinear optical data obtained for the SiNP-1 are within the same range of those of the indium phthalocyanine alone. The nanosecond nonlinear absorption and the optical limiting of the nanocomposites are shown to be dominated by a strong excited state absorption from a two-photon pumped state. Nonlinear scattering effects and strong excited state absorption from a two-photon pumped state account for the enhanced optical limiting behaviour of SiMNP-1 relative to the phthalocyanine alone.

Enhanced optical limiting behaviour of indium phthalocyanine derivatives when in solution or embedded in poly(acrylic acid) or poly(methyl methacrylate) polymers

“…T 2 states than it depends on the population of the T 1 state, while b eff depends more on the population of molecules in the T 1 state. This explanation is reasonable based on our previous finding [40], and the above discussion, that less crowding in the triplet state enhances the triplet-triplet transition (s exc ). Table 2 also shows that the values of s exc decreases with increased aggregation effects.…”

“…(9), we obtained t T of 59.9 ms for 2, with corresponding k value of 5.00 Â 10 4 s À1 ( Table 1). The t T measured for 2 is longer than that of the InTAPPc (51.6 ms) [22], while the corresponding k value is lower for 2 compared to the InTAPPc (1.27 Â 10 6 s À1 ), [40]. A long t T is synonymous to a long triplet absorption period.…”

“…DN = 5.00 Â 10 4 at the T 1 state for 2 implies that the T 1 ! T 2 transitions will be faster, compared to InTAPPc with DN = 1.27 Â 10 6 [40], due to lesser crowding. Thus, complex 2 produces 0.98 of the total number of molecules in transit (N) between the T 1 and the T 2 states.…”

Femtosecond nonlinear absorption and optical limiting action in nanoplatelet CuFe2O4-decorated rGO nanocomposites

“…Graphene possesses interesting nonlinear absorption and refraction properties because of the interband transitions that are independent of the broad wavelength. To improvise the nonlinearity with tunability, graphene oxides (cheaper alternates of graphene) are often decorated with noble metal atom, porphyrin, phthalocyanine or covalent functionalization groups [17][18][19][20]. The remarkable light absorption and broad band emission of oxide derivatives of graphene (GO-graphene oxide, rGO-reduced graphene oxide) due to extended π-conjugate system have shown significant interest in laser damage protecting units.…”

Synthesis and nonlinear optical properties of a novel indium phthalocyanine highly branched polymer

“…The contribution of the ionic components plays a role in the nonlinear optical properties of such materials . Since the first reports on the potential use of phthalocyanines as OL materials in 1989, a lot of research work was devoted to investigate their structural and spectroscopic properties, synthesis techniques, and non‐linear optical (NLO) properties . Some criteria necessary for a large, positive nonlinear absorption are apparent including a large excited‐state cross section σ ex and a large difference between the ground and excited‐state absorption cross sections ( σ ex – σ g ).…”