Study of the Reverse Saturate Absorption in Copper Phthalocyanine Solution

2013 ◽  
Vol 815 ◽  
pp. 165-170
Author(s):  
Fang Li ◽  
Zhi Cong He
Keyword(s):  
Nonlinear Absorption ◽  
Laser Power ◽  
Copper Phthalocyanine ◽  
Photon Absorption ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Promising Candidate ◽  
Sample Concentration ◽  
Excitation Laser ◽  
Excitation Laser Power

The nonlinear absorption (NLA) properties of copper phthalocyanine (CuPc) acetone solution were investigated by femtosecond open-aperture (OA) Z-scan technique. The reverse saturable absorption (RSA) was observed, and it was found that the RSA effect was origin from three-photon absorption. Moreover, the influences of concentration and excitation laser power on the NLA of CuPc solution are studied. Results show that the RSA effect increases with the increase of sample concentration and excitation laser power. It indicates that the CuPc could be a promising candidate for optical limiting material.

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.

scholarly journals Effect of Size on the Saturable Absorption and Reverse Saturable Absorption in Silver Nanoparticle and Ultrafast Dynamics at 400 nm

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Sandeep Kumar Maurya ◽  
Anuradha Rout ◽  
Rashid A. Ganeev ◽  
Chunlei Guo
Keyword(s):  
Nonlinear Absorption ◽  
Laser Pulses ◽  
Acoustic Vibration ◽  
Radial Breathing Mode ◽  
Femtosecond Laser Pulses ◽  
Photon Absorption ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Ultrafast Dynamics ◽  
Ag Nps

Saturable absorption and reverse saturable absorption play an important role in the studies of the nonlinear optical properties of nanoparticles at resonant excitation. With this viewpoint, nonlinear absorption processes of chemically prepared silver nanoparticles in deionized water were studied using femtosecond laser pulses at 400 nm. Our nonlinear absorption study shows that there is competition between saturable absorption and two-photon absorption in prepared Ag NPs which depends on the size of the nanoparticles. We have also studied the ultrafast dynamics associated with nanoparticles which also results in the direct correlation between the ultrafast timescale and the size of the nanoparticle. The excitation of Ag NPs at 400 nm has shown the manifestation of damped oscillation which is attributed to the radial breathing mode oscillation due to acoustic vibration.

Picosecond and femtosecond optical nonlinearities of novel corroles

2012 ◽  
Vol 16 (01) ◽  
pp. 140-148 ◽  
Author(s):  
Syed Hamad ◽  
Surya P. Tewari ◽  
L. Giribabu ◽  
S. Venugopal Rao
Keyword(s):  
Nonlinear Absorption ◽  
Nonlinear Optical ◽  
Laser Pulses ◽  
Photon Absorption ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Closed Aperture ◽  
Absorption Data ◽  
Time Domains ◽  
Fs Laser

We present our results from the experimental and modeling studies of picosecond (ps) and femtosecond (fs) nonlinearities of two novel corroles (a) tritolyl corrole (TTC) (b) triphenyl corrole (TPC) using the Z-scan technique. Both open and closed aperture Z-scan curves were recorded with ~2 ps/~40 fs laser pulses at a wavelength of 800 nm and nonlinear optical coefficients were extracted for both studies. Both the molecules possessed negative nonlinear refractive index (n2) as revealed by signature of the closed aperture data in both (ps and fs) time domains. Picosecond nonlinear absorption data of TPC obtained at a concentration of 5 × 10-4 M demonstrated complex behavior with switching from reverse saturable absorption (RSA) within saturable absorption (SA) at lower peak intensities to RSA at higher peak intensities. TTC data recorded at the similar concentration exhibited saturable absorption (SA) type of behavior at lower peak intensities to switching from RSA with in SA at higher peak intensities. At a concentration of 2.5 × 10-4 M, the ps open aperture data at higher peak intensities illustrated effective three-photon absorption (3PA) for both the molecules. We also report the picosecond spectral dependent Z-scan studies performed at 680 nm, 700 nm, and 740 nm. Nonlinear absorption and refraction of both the samples at these three wavelengths were studied in detail. Femtosecond nonlinear absorption data of TPC and TTC demonstrated the behavior of saturable absorption (SA) at a concentration of 1 × 10-3 M. Solvent contribution to the nonlinearity was also identified. We have also evaluated the sign and magnitude of third order nonlinearity. We discuss the nonlinear optical performance of these organic molecules.

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 Tunable nonlinear optical responses of few-layer graphene through lithium intercalation

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Chenxi Zhang ◽  
Ganying Zeng ◽  
Renyan Zhang ◽  
Yuxiang Tang ◽  
Qirui Liu ◽  
...  
Keyword(s):  
Nonlinear Absorption ◽  
Nonlinear Optical ◽  
Photon Absorption ◽  
Lithium Intercalation ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Absorption Effect ◽  
Layer Graphene ◽  
Ideal System ◽  
Few Layer Graphene

Abstract Intercalation has been demonstrated to be a powerful tool for tuning the physical and chemical properties of two-dimensional (2D) materials, providing the highest possible doping level and an ideal system to study various electronic states. In this work, we demonstrate that the nonlinear absorption effect of few-layer graphene (about 6–8 layers) is changed from saturable absorption (SA) to reverse saturable absorption (RSA) after lithium intercalation. This is attributed to the increase of Fermi energy owing to the charge transfer from Li to graphene layers in intercalated compounds (LiC6). And the change of nonlinear absorption effect is revisable after deintercalation. In addition, the modulation depth of RSA in lithiated graphene is found to rise with the decrease of incident laser wavelength, different from that of pristine graphene. Besides, the dispersion relationships of degenerate and nondegenerate two-photon absorption are analyzed from the results of nonlinear absorption and transient dynamics of lithiated graphene, indicating the 1.91–2.21 eV upshift of the Fermi surface. Our findings of the intercalation-tunable nonlinear optical absorption effect pave the way for the construction of nonlinear optical devices based on 2D intercalation compounds.

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.

Nonlinear absorption in tetrathia[22]porphyrin(2.1.2.1)s: visualizing strong reverse saturable absorption at non-resonant excitation

RSC Advances ◽  
2016 ◽  
Vol 6 (27) ◽  
pp. 22659-22663 ◽  
Author(s):  
Kamaljit Singh ◽  
Shafali Arora ◽  
Krishnandu Makhal ◽  
Paramjit Kaur ◽  
Debabrata Goswami
Keyword(s):  
Nonlinear Absorption ◽  
Potential Application ◽  
Optically Active ◽  
Resonant Excitation ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Threshold Values ◽  
Optical Limiters ◽  
The Family ◽  
New Entry

meso-Substituted neutral, aromatic tetrathia[22]porphyrin(2.1.2.1)s represent a new entry in the family of nonlinear optically active porphyrins. The low fluence threshold values of these porphyrins endorse potential application as optical limiters.

Nonlinear Absorption Properties of Spherical Gold Colloidal Nanoparticles

2012 ◽  
Vol 476-478 ◽  
pp. 923-927 ◽  
Author(s):  
Chan Zheng ◽  
Xiao Yun Ye ◽  
Xue Qing Xiao
Keyword(s):  
Nonlinear Absorption ◽  
Laser Pulses ◽  
Phase Method ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Colloidal Nanoparticles ◽  
Free Carrier Absorption ◽  
Absorption Properties ◽  
Liquid Phase Method ◽  
Carrier Absorption

Spherical gold colloidal nanoparticles were prepared used traditional liquid phase method and the corresponding nonlinear absorption properties were investigated by open aperture Z-scan technique using 8 ns laser pulses of 532 nm. The gold colloidal nanoparticles exhibited a transform from saturable absorption (SA) to reverse saturable absorption (RSA) at relatively higher irradiation intensities. The SA behavior presumably owes to the bleach of ground-state surface plasmon resonance (SPR) absorption, while the RSA might result from high excited-stated free carrier absorption.

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.

Dependence of the Raman Spectrum of Silicon Nanowires on the Wire Environment

2006 ◽  
Vol 963 ◽  
Author(s):  
Harald M. Scheel ◽  
S. Reich ◽  
C. Thomsen
Keyword(s):  
Silicon Nanowires ◽  
Laser Power ◽  
Silicon Oxide ◽  
Thermal Contact ◽  
Strong Dependence ◽  
Surrounding Medium ◽  
Volume Ratio ◽  
Optical Measurements ◽  
Excitation Laser ◽  
Excitation Laser Power

ABSTRACTThe large surface to volume ratio in nanometer sized wire structures cause a strong dependence of the optical Raman mode on the thermal conductivity of a surrounding medium. On the basis of optical measurements on silicon nanowires as a function of excitation laser power we explain the very large red-shifted Raman spectra observed already for moderate laser powers. This thermal effect is enhanced by a silicon oxide sheath, rendering a reduced thermal contact of the wires to the substrate. The intrinsic redshift due to spatial confinement in silicon nanowires is found to be smaller than 2 cm−1.

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