Nonlinear optical interactions of Co: ZnO nanoparticles in continuous and pulsed mode of operations

RSC Advances ◽  
2015 ◽  
Vol 5 (98) ◽  
pp. 80756-80765 ◽  
Author(s):  
Rajeswari Ponnusamy ◽  
Dhanuskodi Sivasubramanian ◽  
P. Sreekanth ◽  
Vinitha Gandhiraj ◽  
Reji Philip ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Zno Nanoparticles ◽  
Nonlinear Optical ◽  
Photon Absorption ◽  
Thermal Lensing ◽  
Saturable Absorption ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Pulsed Mode ◽  
Limiting Behaviour

Thermal lensing and two photon absorption with saturable absorption based optical limiting behaviour in Co: ZnO nanoparticles under CW and pulsed Nd: YAG laser irradiation.

Nonlinear Absorption and Limiting Behaviour of Monoclinic and Orthorhombic Copper Niobate

2017 ◽  
Vol 865 ◽  
pp. 20-24
Author(s):  
N. Priyadarshani ◽  
T.C. Sabari Girisun
Keyword(s):  
Nonlinear Absorption ◽  
Orthorhombic Phase ◽  
Optical Nonlinearity ◽  
Photon Absorption ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Pore Networks ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Limiting Behaviour

Monoclinic and orthorhombic phase of copper niobate was prepared by simple solid state reaction (700°C, 900°C for 12 hours). Formation of two polymorphic phases of CuNb2O6 was ascertained by XRD and FTIR analysis. FESEM showed the presence of pore networks in both phases. Third-order optical nonlinearity and their limiting behaviour were studied by Z-scan technique using Ti: Sapphire laser (800 nm, 150 fs, 80 MHz). Both phases of copper niobate exhibit reverse saturable absorption. The observed optical limiting action was ascribed due to two-photon absorption process. Monoclinic copper niobate shows almost 100 times stronger nonlinear absorption behaviour than orthorhombic copper niobate due to peculiar distortion of NbO6 octahedra. Monoclinic copper niobate with high two photon absorption coefficient (85x10-10 m/W) and low limiting threshold (0.21 μJ/cm2) can be a better alternate for benchmark optical limiters like carbon nanotubes.

scholarly journals Nonlinear Absorption and Ultrafast Dynamics of Ag Nanoparticle

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 233
Author(s):  
Jijuan Jiang ◽  
Jun Wang ◽  
Tong Wu ◽  
Yachen Gao
Keyword(s):  
Silver Nanoparticles ◽  
Time Constant ◽  
Laser Intensity ◽  
Photon Absorption ◽  
Saturable Absorption ◽  
Phonon Coupling ◽  
Saturated Absorption ◽  
Coupling Process ◽  
Two Photon Absorption ◽  
Two Photon

Resonant nonlinear optical absorption of silver nanoparticles was studied experimentally via open aperture Z-scan using 130 fs, 400 nm laser pulses. Experimental results show that, at low laser intensity, silver nanoparticles can exhibit saturated absorption. While at high laser intensity, it shows reverse saturated absorption. The saturable absorption is explained in terms of ground state plasmon bleaching, while the reverse saturable absorption is believed to be from two-photon absorption. Saturable optical intensity and two-photon absorption coefficient were obtained to be 1.3×1010 W/m2 and 3.3×10−10 m/W, respectively. The energy relaxation process of Ag nanoparticles after laser excitation was studied via pump-probe technique at 400 nm. Experimental results demonstrated that energy relaxation included electron-phonon coupling process with time constant τ1=(713±50) fs, and phonon-phonon coupling process with time constant τ2=(25.2±3) ps, respectively.

scholarly journals Nonlinear Optical Pigments. Two-Photon Absorption in Crosslinked Conjugated Polymers and Prospects for Remote Nonlinear Optical Thermometry

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1670
Author(s):  
Jan K. Zaręba ◽  
Marcin Nyk ◽  
Marek Samoć
Keyword(s):  
Solid State ◽  
Conjugated Polymers ◽  
Nonlinear Optical ◽  
Photon Absorption ◽  
Model Compounds ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Sensing Applications ◽  
Spectrally Resolved ◽  
The Impact

Nonlinear optical (NLO) pigments are compounds insoluble in solvents that exhibit phenomena related to nonlinear optical susceptibilities (χ(n) where n = 2,3,...), e.g., two-photon absorption (2PA) which is related to the imaginary part of χ(3). Determination of spectrally-resolved 2PA properties for NLO pigments of macromolecular nature, such as coordination polymers or crosslinked polymers, has long been a challenging issue due to their particulate form, precluding characterizations with standard techniques such as Z-scan. In this contribution, we investigate thus far unknown spectrally-resolved 2PA properties of a new subclass of NLO pigments—crosslinked conjugated polymers. The studied compounds are built up from electron-donating (triphenylamine) and electron-withdrawing (2,2’-bipyridine) structural fragments joined by vinylene (Pol1) or vinyl(4-ethynylphenyl) (Pol2) aromatic bridges. 2PA properties of these polymers have been characterized in broad spectral range by specially modified two-photon excited fluorescence (TPEF) techniques: solid state TPEF (SSTPEF) and internal standard TPEF (ISTPEF). The impact of self-aggregation of aromatic backbones on the 2PA properties of the polymers has been evaluated through extended comparisons of NLO parameters, i.e., 2PA cross sections (σ2) and molar-mass normalized 2PA merit factors (σ2/M) with those of small-molecular model compounds: Mod1 and Mod2. By doing this, we found that the 2PA response of Pol1 and Pol2 is improved 2–3 times versus respective model compounds in the solid state form. Further comparisons with 2PA results collected for diluted solutions of Mod1 and Mod2 supports the notion that self-aggregated structure contributes to the observed enhancement of 2PA response. On the other hand, it is clear that Pol1 and Pol2 suffer from aggregation-caused quenching phenomenon, well reflected in time-resolved fluorescence properties as well as in relatively low values of quantum yield of fluorescence. Accordingly, despite improved intrinsic 2PA response, the effective intensity of two-photon excited emission for Pol1 and Pol2 is slightly lower relative to Mod1 and Mod2. Finally, we explore temperature-resolved luminescence properties under one- (377 nm), two- (820 nm), and three-photon excitation (1020 nm) conditions of postsynthetically Eu3+-functionalized material, Pol1-Eu, and discuss its suitability for temperature sensing applications.

Third-order nonlinear optical properties and two-photon absorption in branched oligothienylenevinylenes

2002 ◽  
Vol 209 (4-6) ◽  
pp. 461-466 ◽  
Author(s):  
I. Fuks-Janczarek ◽  
J-M. Nunzi ◽  
B. Sahraoui ◽  
I.V. Kityk ◽  
J. Berdowski ◽  
...  
Keyword(s):  
Optical Properties ◽  
Nonlinear Optical ◽  
Nonlinear Optical Properties ◽  
Photon Absorption ◽  
Third Order ◽  
Two Photon Absorption ◽  
Two Photon
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