New concentration gradient designs for reverse saturable absorption limiters

1997 ◽  
Author(s):  
Daniel G. McLean
Keyword(s):  
Concentration Gradient ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption

scholarly journals Large Optical Nonlinearity of the Activated Carbon Nanoparticles Prepared by Laser Ablation

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 737
Author(s):  
Yasin Orooji ◽  
Hamed Ghanbari Gol ◽  
Babak Jaleh ◽  
Mohammad Reza Rashidian Vaziri ◽  
Mahtab Eslamipanah
Keyword(s):  
Electron Microscopy ◽  
Activated Carbon ◽  
Laser Ablation ◽  
Carbon Nanoparticles ◽  
Morphological Properties ◽  
Excitation Wavelength ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
High Porosity ◽  
Nlo Properties

Carbon nanoparticles (CNPs) with high porosity and great optical features can be used as a luminescent material. One year later, the same group investigated the NLO properties CNPs and boron-doped CNPs by 532 nm and 1064 nm laser excitations to uncover the underlying physical mechanisms in their NLO response. Hence, a facile approach, laser ablation technique, was employed for carbon nanoparticles (CNPs) synthesis from suspended activated carbon (AC). Morphological properties of the prepared CNPs were studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). UV-Vis and fluorescence (FL) spectra were used to optical properties investigation of CNPs. The size distribution of nanoparticles was evaluated using dynamic light scattering (DLS). The nonlinear optical (NLO) coefficients of the synthesized CNPs were determined by the Z-scan method. As a result, strong reverse saturable absorption and self-defocusing effects were observed at the excitation wavelength of 442 nm laser irradiation. These effects were ascribed to the presence of delocalized π-electrons in AC CNPs. To the best of our knowledge, this is the first study investigating the NLO properties of the AC CNPs.

Increasing the triplet lifetime and extending the ground-state absorption of biscyclometalated Ir(iii) complexes for reverse saturable absorption and photodynamic therapy applications

2016 ◽  
Vol 45 (41) ◽  
pp. 16366-16378 ◽  
Author(s):  
Chengzhe Wang ◽  
Levi Lystrom ◽  
Huimin Yin ◽  
Marc Hetu ◽  
Svetlana Kilina ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Ground State ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Ground State Absorption ◽  
Saturable Absorbers ◽  
Triplet Lifetime

Tuning the photophysics of cationic Ir(iii) complexes via π-expansive ligands dramatically impacts their applications as broadband reverse saturable absorbers and in photodynamic therapy and theranostics.

Optimization of Reverse Saturable Absorber Limiters: Material Requirements and Design Considerations

1994 ◽  
Vol 374 ◽  
Author(s):  
D. J. Hagan ◽  
T. Xia ◽  
A. Dogariu ◽  
A. A. Said ◽  
E. W. Van Stryland
Keyword(s):  
Nonlinear Absorption ◽  
Entire Length ◽  
Nonlinear Material ◽  
Propagation Path ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Individual Element ◽  
Analytic Model ◽  
Molecular Density ◽  
Optimized Distribution

AbstractWe present numerical beam-propagation simulations of optimized reverse-saturable absorption (RSA) based optical limiters where the depth of focus of the input beam is much smaller than the thickness of the nonlinear material. The optimization is achieved by allowing the molecular concentration to vary along the propagation path, allowing the entire length of the limiter to reach the maximum possible nonlinear absorption before eventual damage to the limiter. We review in detail the analytic model originally derived by Miles [1] to determine the design and performance of such limiters. This model requires the usual 5-level model used in the numerical solution to be approximated by a quasi-three-level system. We show that this effective 3-level excited-state cross section is both pulsewidth and fluence dependent. The numerical propagation output shows that there is considerable diffractive beam distortion, which cannot be accounted for in the analytic model. The end result is that while there is qualitative agreement with numerical results, the magnitude of the limited output can be an order-of-magnitude underestimated. We determine that the fluence level at all parts of the limiter must be at least ten times the saturation fluence to efficiently utilize the nonlinear absorption. We further describe how the optimized distribution of molecular density is the limit of the multi-element tandem limiter for an infinite number of elements. By carefully accounting for saturation over the entire length of each individual element, we show how a multi-element limiter may be designed to closely approach the performance of the optimized distribution for as few as four elements. With current materials technology the damage threshold of solid hosts needed to vary the molecular density is much lower than that of glass cuvettes used for liquid based limiters. Therefore, a multi-element liquid based tandem limiter can be used in full saturation so that better limiter performance should be obtained. Ultimately, however, the operation of all RSA-based limiters involves a strict trade-off between performance and linear transmittance.

Effects of extending the π-conjugation of the acetylide ligand on the photophysics and reverse saturable absorption of Pt(ii) bipyridine bisacetylide complexes

2016 ◽  
Vol 18 (41) ◽  
pp. 28674-28687 ◽  
Author(s):  
Taotao Lu ◽  
Chengzhe Wang ◽  
Levi Lystrom ◽  
Chengkui Pei ◽  
Svetlana Kilina ◽  
...  
Keyword(s):  
Excited State ◽  
Excited States ◽  
Substituent Effect ◽  
Excited State Absorption ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Triplet Excited State ◽  
Near Ir ◽  
Terminal Substituent ◽  
Acetylide Ligand

Extending the acetylide ligand π-conjugation diminishes the terminal substituent effect on the lowest excited states, but expands the triplet excited-state absorption to the near-IR region.

Reverse saturable absorption and nonlinear refraction of ultrathin ZrS3nanobelts

Nanoscale ◽  
2016 ◽  
Vol 8 (19) ◽  
pp. 10371-10379 ◽  
Author(s):  
Jia-Jing Wu ◽  
You-Rong Tao ◽  
Jia-Nan Wang ◽  
Zhong-Yu Wu ◽  
Lei Fan ◽  
...  
Keyword(s):  
Nonlinear Refraction ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption

Reverse saturable absorption and optical limiting in indanthrone dyes

1996 ◽  
Vol 62 (3) ◽  
pp. 293-297 ◽  
Author(s):  
Rama Chari ◽  
S. R. Mishra ◽  
H. S. Rawat ◽  
S. M. Oak
Keyword(s):  
Optical Limiting ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption

scholarly journals Reverse saturable absorption in 5,10,15,20-Tetra(4-pyridyl)-21H,23H-porphyrin with ruthenium outlying complexes

2006 ◽  
Vol 17 (7) ◽  
pp. 1377-1782 ◽  
Author(s):  
Newton M. Barbosa Neto ◽  
Samuel L. Oliveira ◽  
Ilde Guedes ◽  
Luis R. Dinelli ◽  
Lino Misoguti ◽  
...  
Keyword(s):  
Saturable Absorption ◽  
Reverse Saturable Absorption

scholarly journals Aspect-ratio Dependence of Optical Nonlinearities on Resonance with Longitudinal Surface Plasmon in Au Nanorods: Unique Character versus Common Behavior

2018 ◽  
Vol 1 (1) ◽  
pp. 001-007
Author(s):  
Science Nature
Keyword(s):  
Aspect Ratio ◽  
Surface Plasmon ◽  
Nonlinear Behavior ◽  
Dipole Approximation ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Optical Nonlinearities ◽  
Ratio Dependence ◽  
Unique Character ◽  
Metal Metal

Unique character and common behavior are two distinguished things. In frontier nanoscience and nanotechnology, unique characters were normally obtained in some novel exotics materials such as metal-metal core-shell materials, metallic-semiconducting hybrid nanomaterials, and  organic-inorganics complex nano-compounds. On the other hand, normal behavior of natural phenomena including in nano-size objects were obviously predicted based on their exact size related to confinement effect, and capability to interact with another physical system  in nature.  Here, we report an example of unique character due to evolution nonlinear behavior observed in gold nanorod with their aspect-ratio dependence of optical nonlinearities investigated by femtosecond Z-scan measurements closed to resonance longitudinal surface plasmon peak in gold nanorods (Au NRs). Saturable absorption manifests itself at low excitation (laser irradiances < ~7.0 GW/cm2), while reverse saturable absorption dominates at higher excitation. Both the nonlinear processes are found to increase with the aspect ratio of Au NRs.  Based on the discrete dipole approximation, qualitative explanations are presented for the observed nonlinear behavior. While common behavior in metallic quantum dots or other shapes of metallic nanomaterials was not the significant in our observation.  

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