In view of a possible application in optical data storage devices, diffraction grating efficiency of an organic dye, Acid Fuchsin doped in PMMA matrix was studied under excitation with CW diode pumped Nd: YAG laser at 532 nm. The open aperture Zscan of dye doped polymer displayed saturable absorption and the closed aperture Z-scan of the samples exhibited negative nonlinearity. The diffraction ...

Abstract We study supercontinuum (SC) generation in graphene-covered nanowires based on a generic model that correctly accounts for the evolution of photon number under Kerr and two-photon absorption processes, influence graphene is treated within framework saturable photoexcited-carrier refraction. discuss role various effects SC by thorough analysis short-pulse propagation two different kinds...

We employed open-aperture Z-scan technique to unveil the third-order optical nonlinearity in ZnCo2O4 (ZCO) microflowers. Our results indicate that intersystem crossing (ISC) lifetime can be used as simple tool demonstrate remarkably contrasting ZCO. Ultrafast transient absorption measurements reveal ISC from singlet triplet state takes place 5 ps. For femtosecond laser pulses, when pulse durati...

The graphene-light interaction in a waveguide can be optimized through the design. In case of nonlinear optical devices, such as saturable absorbers, this optimization requires knowledge actual intensity that quantifies with mode. work we propose parameters correctly quantify strength absorption. We show graphene on D-fiber absorber characterized absorption coefficient and properly defined satu...

The presense of saturable absorption (SA) in zinc nanoparticles photodeposited onto the core of an optical fiber by a coherent source is reported. An analysis based on Mie theory was carried out to demonstrate the interaction of the absorption coefficient with the particles sizes in the proximity of surface plasmon resonance in the infrared region. This work opens a new scheme for the implement...

We report the measurement of reverse saturable absorption in four cubanelike transition-metal clusters with nanosecond laser pulses. We also present a five-level rate-equation model in which ionization and germinate recombination are included. A comparison between the model and the measured data shows that the population of the triplet states is generated mainly through the ionization–recombina...

Limiting devices protect sensitive optical elements from laser-induced damage (LID). Passive devices use focusing optics to concentrate the light through a nonlinear optical (NLO) element (or elements) to reduce the limiting threshold. Unfortunately, these NLO elements may themselves undergo LID for high inputs, restricting the useful dynamic range (DR). Recently, efforts at optimizing this DR ...

Two-photon absorption (2PA) and excited state absorption (ESA) properties of axial-bonding type hybrid porphyrin arrays are investigated in the picosecond regime under single-photon resonant excitation condition. A crossover from reverse saturable absorption (RSA) to saturable absorption (SA) and back to RSA is observed with the increase of excitation intensity. In the corresponding intensity r...