scholarly journals Paradoxical combination of saturable absorption and reverse-saturable absorption in plasmon semiconductor nanocrystals

2020 ◽  
Vol 2 (4) ◽  
pp. 1676-1684 ◽  
Author(s):  
Xiangling Tian ◽  
Rongfei Wei ◽  
Dandan Yang ◽  
Jianrong Qiu
Keyword(s):  
Ground State ◽  
Semiconductor Nanocrystals ◽  
Photon Absorption ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Zno Nanocrystals ◽  
Doped Zno

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.

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.

ABSORPTION, EMISSION AND NONLINEAR SPECTROSCOPIC CHARACTERIZATION OF REACTIVE DYE

2006 ◽  
Vol 15 (04) ◽  
pp. 481-490
Author(s):  
SHENG-LI GUO ◽  
ZHUN GUO ◽  
T. SUSDORF ◽  
TIAN-DE CAO
Keyword(s):  
Ground State ◽  
Nonlinear Optical ◽  
Spectroscopic Characterization ◽  
Reactive Dye ◽  
Mode Locking ◽  
Photon Absorption ◽  
Quantum Yields ◽  
Saturable Absorption ◽  
Potential Candidate ◽  
Reactive Orange

An optical spectroscopic characterization is carried out on a reactive dye (reactive orange 1). This dye is widely applied in textile coloration. It is a potential candidate for photonics applications. Its absorption cross-section spectra are measured. A fluorescence spectroscopic characterization is undertaken by measuring the fluorescence quantum distributions and fluorescence quantum yields. The saturable absorption is studied by nonlinear transmission measurements with intense picosecond laser pulses (second harmonic pulses of a mode-locked Nd :glass laser). The nonlinear optical absorption and refraction coefficients are measured by using the top-hat Z-scan technique at a wavelength of 532 nm with 35 ps duration pulses. Reactive orange 1 has the two-photon absorption coefficient of 1.20 cm/GW and the nonlinear refraction coefficient of -7.33 × 10-6 cm2/GW, respectively. In reactive orange 1, there occurs fast ground-state recovery by internal conversion likely via conical intersections. Low excited-state absorption and fast ground-state absorption recovery make it an ideal candidate for passive mode-locking of picosecond and femtosecond lasers as well as for fast nonlinear optical gating.

Phosphorescence Studies of Reverse Saturable Absorption Materials

1999 ◽  
Vol 597 ◽  
Author(s):  
E. S. Pooler ◽  
C. M. Clark ◽  
S. M. Kirkpatrick
Keyword(s):  
Energy Level ◽  
Triplet State ◽  
Ground State ◽  
Relative Energy ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Absorption And Emission ◽  
Host Polymer

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.

Synthesis of New Multifunctional Polymers inCorporating BIS-(Diphenylamino)Diphenylpolyene Moieties

1997 ◽  
Vol 488 ◽  
Author(s):  
C. W. Spangler ◽  
T. Faircloth ◽  
E. H. Elandaloussi ◽  
B. Reeves
Keyword(s):  
Photon Absorption ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
New Materials ◽  
Double Bonds ◽  
Model Compounds ◽  
Optical Limiters ◽  
Oxidative Doping ◽  
Multifunctional Polymers

AbstractA series of bis-(diphenylamino)diphenylpolyenes containing up to eight double bonds has been synthesized, both as parent model compounds, and functionalized for attachment as pendant chromophores. Oxidative doping of these new materials yields exceptionally stable bipolaronlike dications, even at the triene level. These new materials show promise as bimechanistic optical limiters by reverse saturable absorption and by 2-photon absorption.

scholarly journals Broadband Visible Nonlinear Absorption and Ultrafast Dynamics of the Ti3C2 Nanosheet

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2544
Author(s):  
Yabin Shao ◽  
Chen Chen ◽  
Qing He ◽  
Wenzhi Wu ◽  
Chensha Li ◽  
...  
Keyword(s):  
Nonlinear Absorption ◽  
Transient Absorption ◽  
Laser Energy ◽  
Visible Region ◽  
Photon Absorption ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Ultrafast Dynamics ◽  
Fast Decay ◽  
Broadband Absorption

The Ti3C2 nanosheet, as a new two-dimensional (2D) group, has been found to have attractive characteristics as material for electromagnetic shielding and energy storage. In this study, the nonlinear broadband absorption and ultrafast dynamics of the Ti3C2 nanosheet were investigated using nanosecond open-aperture Z-scan and transient absorption techniques. The mechanism of two-photon absorption (TPA) was revealed in the visible region (475–700 nm). At lower incident energies, nonlinear absorption could not happen. When the laser energy increased to 0.64 GW/cm2, electrons in the valence band could absorb two photons and jump to the conduction band, with TPA occurring, which meant that the sample exhibited reverse saturable absorption (RSA). In addition, when transient absorption was used to investigate the ultrafast carrier dynamics of the sample, it demonstrated that the relaxation contains a fast decay component and a slow one, which are obtained from electron–phonon and phonon–phonon interactions, respectively. Moreover, with the increasing pump fluence, the fast decay lifetime τ1 increased from 3.9 to 4.5 ps, and the slow one τ2 increased from 11.1 to 13.2 ps. These results show that the Ti3C2 nanosheet has potential applications in broadband optical limiters.

The high-order optical nonlinearity of 2,11,20,29-tetrabromo-2,3-naphthalocyanine iron

2018 ◽  
Vol 22 (09n10) ◽  
pp. 863-867
Author(s):  
Wang Zhang ◽  
Chunying He ◽  
Lining Zhang ◽  
Li Jiang ◽  
Yijun Yuan ◽  
...  
Keyword(s):  
Excited State ◽  
Cross Sections ◽  
Ground State ◽  
Nonlinear Refraction ◽  
Optical Nonlinearity ◽  
High Order ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Triplet Excited State ◽  
First Excited State

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.

Nonunear Absorption in Phthalocyanines and Naphthalocyanines

1993 ◽  
Vol 328 ◽  
Author(s):  
James S. Shirk ◽  
Steven R. Flom ◽  
J. R. Lindle ◽  
F. J. Bartoli ◽  
Arthur W. Snow ◽  
...  
Keyword(s):  
Ground State ◽  
Nonlinear Absorption ◽  
Optical Limiting ◽  
Wavelength Dependence ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Ground State Absorption

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.

Defect-assisted saturable absorption characteristics in Mn doped ZnO nano-rods

RSC Advances ◽  
2015 ◽  
Vol 5 (108) ◽  
pp. 88767-88772 ◽  
Author(s):  
Avanendra Singh ◽  
Samir Kumar ◽  
Ritwick Das ◽  
Pratap K. Sahoo
Keyword(s):  
Doping Level ◽  
Zno Nanorods ◽  
Photon Absorption ◽  
Saturable Absorption ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Nano Rods ◽  
Doped Zno ◽  
Mn Doped ◽  
Absorption Characteristics

After reaching a threshold doping level of Mn, it is possible to alter from two photon absorption to saturable absorption in ZnO nanorods.

Ultrafast third order nonlinear optical properties of water soluble zinc-octacarboxy-phthalocyanine

2012 ◽  
Vol 16 (09) ◽  
pp. 1015-1023 ◽  
Author(s):  
M. Bala Murali Krishna ◽  
L. Giribabu ◽  
D. Narayana Rao
Keyword(s):  
Optical Switching ◽  
Nonlinear Optical ◽  
Water Soluble ◽  
Photon Absorption ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Third Order ◽  
Two Photon Absorption ◽  
Time Domains ◽  
Soluble Zinc

Synthesis and measurements of third order nonlinear optical (NLO) coefficients of water soluble zinc octacarboxy phthalocyanine (ZnOCPc) are reported here using different laser pulse durations. Nonlinear absorption and refraction behaviour in the nanosecond (ns), picosecond (ps) and femtosecond (fs) time domains were studied in detail. Three-photon absorption was the prevalent mechanism with femtosecond laser excitation whereas strong reverse saturable absorption due to dominant two-photon absorption (TPA) was observed with picosecond and nanosecond excitations. We have evaluated the sign and magnitude of the third order nonlinearity in fs, ps, and ns regimes. We observed large off-resonant second order hyperpolarizability (γ) with ultrafast nonlinear optical response in the femtosecond domain using degenerate four wave mixing (DFWM) technique. We also report the optical limiting characteristics and figure of merit (FOM) of ZnOCPc for optical switching.

Two-Photon Absorption in Polybenzidine

1994 ◽  
Vol 374 ◽  
Author(s):  
F. J. Aranda ◽  
C. F. Cheng ◽  
D. V. G. L. N. Rao ◽  
J. A. Akkara ◽  
D. L. Kaplan ◽  
...  
Keyword(s):  
Slow Component ◽  
Photon Absorption ◽  
Polymerization Reaction ◽  
Imaginary Component ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Nonlinear Optical Susceptibility ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Nanosecond Pulses

AbstractPolymers of Benzidine were synthesized by hydrogen peroxide reaction catalyzed by horseradish peroxidase enzyme. The polymerization reaction was carried out at room temperature in a monophasic organic solvent with a small amount of water at pH 7.5.The technique of degenerate four-wave mixing (DFWM) with nanosecond and picosecond pulses was employed to measure the third-order nonlinear optical susceptibility χ. The samples were studied in solution in Dimethyl sulfoxide:Methanol in volume ratio 4:1. The observed values are of order 10−9 to 10−8esu. Measurements on a thin film agree approximately with the extrapolated values fron solution measurements. Picosecond time resolved measurements indicate a pulse-width limited response followed by a small slow component. Investigation of the total energy transmission as a function of the incident intensity and fluence at 532 nm for pico- and nanosecond pulses indicates reverse saturable absorption. As we observe the nanosecond and picosecond curves to be superimposed for the intensity plot but not for fluence, we conclude that the nonlinearity is predominantly due to two-photon absorption. Numerical analysis of the data yields a value of 12.25 cm/GW for the two-photon absorption coefficient β. The imaginary component of χ obtained is 5 × 10−9esu. The material appears to be a good candidate for applications in optical power limiting and switching.

Sign in / Sign up

Export Citation Format

Share Document