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 ◽  
...  

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.

1993 ◽  
Vol 328 ◽  
Author(s):  
James S. Shirk ◽  
Steven R. Flom ◽  
J. R. Lindle ◽  
F. J. Bartoli ◽  
Arthur W. Snow ◽  
...  

ABSTRACTThe wavelength dependence of the nonlinear absorption for lead tetrakis (cumyl-phenoxy) phthalocyanine (PbPc(CP)4) and lead octa (α-pentoxy) napthalocyanine (PbNc(α-PO)8) are reported. The ground state absorption and the reverse saturable absorption are substantially red shifted in PbNc (α-PO)8 as expected. Such control over the reverse saturable absorption is crucial to design optical limiting materials for specific wavelength ranges.


1999 ◽  
Vol 597 ◽  
Author(s):  
E. S. Pooler ◽  
C. M. Clark ◽  
S. M. Kirkpatrick

AbstractPhosphorescence studies of reverse saturable absorption materials (RSA) are discussed. Absorption and emission measurements of an RSA material, specifically Zinc 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetraphenylporphyrin (ZnOBP), are performed in a proprietary host polymer. Spectra are analyzed to estimate the relative energy level of the first triplet state of ZnOBP with respect to the ground state.


2018 ◽  
Vol 22 (09n10) ◽  
pp. 863-867
Author(s):  
Wang Zhang ◽  
Chunying He ◽  
Lining Zhang ◽  
Li Jiang ◽  
Yijun Yuan ◽  
...  

A novel naphthalocyanine 2,11,20,29-tetrabromo-2,3-naphthalocyanine iron was synthetized. Its optical nonlinearity was investigated using the Z-scan technique. Reverse saturable absorption and high-order optical nonlinear refraction were detected. The absorption cross sections of the ground state, the singlet first excited state and the triplet first excited state were fitted to be 3.2 × 10[Formula: see text] cm[Formula: see text], 6.2 × 10[Formula: see text] cm[Formula: see text] and 4.6 × 10[Formula: see text] cm[Formula: see text], respectively. Fits also gave 1.17 × 10[Formula: see text] cm[Formula: see text] for the refractive volume of the ground state, 0.6 for the ratio of the refractive volume of the singlet first excited state to the ground state and 2.7 for the ratio of refractive volume of the first triplet excited state to the ground state.


2000 ◽  
Vol 09 (04) ◽  
pp. 505-521 ◽  
Author(s):  
J. CALLAGHAN ◽  
W. J. BLAU ◽  
F. Z. HENARI

Investigations of the reverse saturable absorption behaviour of Fullerenes C 60 and C 70 and some of their Pt and Pd metal derivatives have been carried out with picosecond pulses at 532 nm. From intensity dependent transmission measurements, coupled with a population level kinetic analysis, excited state cross sections were determined for the materials. These show that C 60 possesses the largest excited state to ground state cross-section ratio and that, of the materials studied, it offers the best optical limiting ability around 532 nm. C 70, due to its large ground state absorption, has been shown not to be an efficient limiter. The metal derivatives perform better than C 70 but less efficiently than C 60.


2000 ◽  
Vol 09 (04) ◽  
pp. 523-530 ◽  
Author(s):  
P. FENEYROU

We report experimental results on a tin phthalocyanine: the nanosecond transient spectroscopy shows a reverse saturable absorption between 490–530 nm and 550–700 nm and the nonlinear transmission provides a better optical power limiting efficiency from 570 nm to 700 nm compared to C 60. This molecule is then combined in a tandem filter with a multiphoton absorber and a mixture of reverse saturable absorbers to achieve neutral-color broadband protection against ns pulses: the transmitted energy is clamped below 2 μ J throughout the visible.


Nanophotonics ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 145-151 ◽  
Author(s):  
Shaimaa I. Azzam ◽  
Alexander V. Kildishev

AbstractAn advanced full-wave time-domain numerical model for reverse saturable absorption (RSA) is presented and verified. Rate equations describing atomic relaxations and excitation dynamics are coupled to the Maxwell equations by using a Lorentzian oscillator, which models the kinetics-dependent light–matter interactions. The presented novel technique provides a versatile multiphysics framework for designing complex structures and integrating diverse material models that were not previously possible. The multiphysics framework allows capturing the behavior of the RSA materials embedded in artificial photonic nanostructures that cannot be analyzed with established techniques such as the Beer–Lambert law. To showcase the importance of the full-wave RSA analysis coupled to carrier kinetics, we analyze two plasmon-enhanced optical limiters: a metal grating and a Fabry–Perot cavity-like structure where we decrease the unenhanced limiter threshold by a factor of 3 and 13, respectively. This is a promising approach for developing RSA devices operating at reduced illumination levels and thereby significantly expanding their area of applicability to areas such as protective eyewear and automatically dimmed windows. By exploring the dynamic behavior of a given RSA system, this framework will provide critical insights into the design of transformative photonic devices and their complementary optical characterization, and serve as an invaluable utility for guiding the development of synthetic absorbing materials. We believe that our multiphysics models are crucial enabling tools that lay a necessary foundation for the numerical machinery required for the realization and optimization of optical limiting and all-optical switching systems.


2020 ◽  
Vol 2 (4) ◽  
pp. 1676-1684 ◽  
Author(s):  
Xiangling Tian ◽  
Rongfei Wei ◽  
Dandan Yang ◽  
Jianrong Qiu

The competition between plasma ground-state bleaching and three-photon absorption is demonstrated to be responsible for the transition between saturable absorption and reverse saturable absorption in aluminum-doped ZnO nanocrystals.


1997 ◽  
Vol 479 ◽  
Author(s):  
M. Brunel ◽  
F. Chaput ◽  
S. A. Vinogradov ◽  
B. Campagne ◽  
M. Canva ◽  
...  

AbstractPd and Zn - tetraphenyltetrabenzoporphyrins (PdTPTBP and ZnTPTBP), hexacyanin 3 (HITCI), and substituted phthalocyanines were incorporated in solid-state matrices (xerogels) using a sol-gel process. Nonlinear reverse saturable absorption was observed with those materials when they were illuminated with nanosecond laser pulses at 532 nm, or other wavelengths in the visible spectrum (between 450 nm and 630 nm). PdTPTBP doped xerogels exhibit a nonlinear activation threshold of about 10 mJ/cm , which is much lower than the value of 80 mJ/cm2 obtained under similar conditions with classical Al phthalocyanine chloride, or HITCI molecules. Solid state “red active” reverse saturable absorbers can be obtained with substituted phthalocyanines doped xerogels. The different experimental results are discussed using classical 4- energy level diagrams.


2020 ◽  
Vol 44 (2) ◽  
pp. 456-465 ◽  
Author(s):  
Li Wang ◽  
Peng Cui ◽  
Levi Lystrom ◽  
Jiapeng Lu ◽  
Svetlana Kilina ◽  
...  

Fluorenyl substitution at the diimine ligand broadened the excited-state absorption to near-IR, and enhanced reverse saturable absorption at 532 nm for the cationic Ir(iii) complexes.


Nanophotonics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1741-1751
Author(s):  
Young In Jhon ◽  
Jinho Lee ◽  
Young Min Jhon ◽  
Ju Han Lee

Abstract Metallic 2D materials can be promising saturable absorbers for ultrashort pulsed laser production in the long wavelength regime. However, preparing and manipulating their 2D structures without layer stacking have been nontrivial. Using a combined experimental and theoretical approach, we demonstrate here that a metallic titanium carbide (Ti3C2Tx), the most popular MXene 2D material, can have excellent nonlinear saturable absorption properties even in a highly stacked state due to its intrinsically existing surface termination, and thus can produce mode-locked femtosecond pulsed lasers in the 1.9-μm infrared range. Density functional theory calculations reveal that the electronic and optical properties of Ti3C2Tx MXene can be well preserved against significant layer stacking. Indeed, it is experimentally shown that 1.914-μm femtosecond pulsed lasers with a duration of 897 fs are readily generated within a fiber cavity using hundreds-of-layer stacked Ti3C2Tx MXene saturable absorbers, not only being much easier to manufacture than mono- or few-layered ones, but also offering character-conserved tightly-assembled 2D materials for advanced performance. This work strongly suggests that as-obtained highly stacked Ti3C2Tx MXenes can serve as superb material platforms for versatile nanophotonic applications, paving the way toward cost-effective, high-performance photonic devices based on MXenes.


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