Nanosecond and ultrafast optical power limiting in luminescent Fe2O3 hexagonal nanomorphotype

Abstract

Efficient ultrafast optical limiting using single walled carbon nanotubes functionalized noncovalently with free base and metalloporphyrins Nonlinear optical absorption and optical power limiting properties of Fe 2 O 3 hexagonal nanomorphotype are investigated using open aperture Z-scan technique with the 5 ns and 100 fs laser pulses, at 532 nm and 800 nm excitation domains. At relatively low pulse energies (below 5 lJ), sample shows saturable absorption (SA), but on going to the higher energies an interesting switchover from saturable absorption to effective two photon absorption is observed in both excitation domains. The magnitude of effective two photon absorption coefficients is calculated to be in the range of 10 À10 m/W for nanosecond and 10 À15 m/W for femtosecond laser pulse energies, respectively. XRD and TEM study reveals the polycrystalline nature, hexagonal morphology, and size of the nanostructure. The luminescence emission property is examined by photoluminescence spectroscopy (PL). It is found that some strange features exist in the luminescence spectra that are consistent with the nanoparticles size distribution. The PL emission lines are explained as originated from various optical band edges due to the size induced quantum confinement and band gap resonant PL absorption/emission behavior of semiconductor nanostructures. V C 2015 AIP Publishing LLC.

Significance of interface barrier at electrode of hematite hydroelectric cell for generating ecopower by water splitting

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Highly Sensitive Ethanol Chemical Sensor Based on Novel Ag-Doped Mesoporous α–Fe2O3 Prepared by Modified Sol-Gel Process

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Tunable Broadband Nonlinear Optical Properties of Black Phosphorus Quantum Dots for Femtosecond Laser Pulses

“…The fitting values of nonlinear absorption coefficient β at 500, 700 and 900 nm were found to be (7.49 ± 0.23) × 10 −3 , (1.68 ± 0.078) × 10 −3 and (0.81 ± 0.03) × 10 −3 cm/GW for BPQDs, respectively. The obtained nonlinear absorption coefficients of these BPQDs are higher than those of other optical-limiting materials such as CdSe QDs with average size of around 2 nm ((1.1 ± 0.15) × 10 −3 cm/GW) [ 49 ], CdO nanoflakes (0.69 × 10 −3 cm/GW) [ 50 ] and Fe 2 O 3 hexagonal nanostructures (0.82 × 10 −3 cm/GW) [ 51 ], obtained by using the similar femtosecond laser pulses. These results indicated that BPQDs can act as good broadband optical-limiting materials in the visible range.…”