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

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.

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Broadband Visible Nonlinear Absorption and Ultrafast Dynamics of the Ti3C2 Nanosheet

Nanomaterials ◽

10.3390/nano10122544 ◽

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.

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Picosecond and femtosecond optical nonlinearities of novel corroles

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s108842461200446x ◽

2012 ◽

Vol 16 (01) ◽

pp. 140-148 ◽

Cited By ~ 38

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.

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Nonlinear Absorption Properties of Spherical Gold Colloidal Nanoparticles

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.476-478.923 ◽

2012 ◽

Vol 476-478 ◽

pp. 923-927 ◽

Cited By ~ 1

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.

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Silver Nanoparticles under Nanosecond Pulsed Laser Excitation as an Intensity Sensitive Saturable Absorption to Reverse Saturable Absorption Switching Material

Photonics ◽

10.3390/photonics8100413 ◽

2021 ◽

Vol 8 (10) ◽

pp. 413

Author(s):

Edappadikkunnummal Shiju ◽

Kaniyarakkal Sharafudeen ◽

T. M. Remya ◽

N. K. Siji Narendran ◽

Palengara Sudheesh ◽

...

Keyword(s):

Silver Nanoparticles ◽

Nonlinear Optical ◽

Second Harmonic ◽

Laser System ◽

Laser Pulses ◽

Optical Nonlinearity ◽

Saturable Absorption ◽

Reverse Saturable Absorption ◽

Closed Aperture ◽

Ag Nps

Optical nonlinearity involved switching draws an important consideration in nonlinear optical studies. Based on that, we explored nonlinear absorption processes in silver nanoparticles synthesized by liquid phase laser ablation technique employing a second harmonic wavelength (532 nm) of Q switched Nd:YAG laser pulses with 7 ns pulse width and 10 Hz repetition rates. The typical surface plasmon resonance induced absorption (~418 nm) confirmed the formation of Ag NPs. The Z-scan technique was used to study the nonlinear optical processes, employing the same laser system used for ablation. Our study reveals that there is an occurrence of a saturable to reverse saturable absorption switching activity in the Ag nanoparticles, which is strongly on-axis input intensity dependent as well. The closed aperture Z-scan analysis revealed the self-defocusing nature of the sample.

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Nonlinear Absorption and Limiting Behaviour of Monoclinic and Orthorhombic Copper Niobate

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.865.20 ◽

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.

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

Nanophotonics ◽

10.1515/nanoph-2021-0173 ◽

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.

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Study of the Reverse Saturate Absorption in Copper Phthalocyanine Solution

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.815.165 ◽

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.

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2D organic-inorganic hybrid perovskite materials for nonlinear optics

Nanophotonics ◽

10.1515/nanoph-2020-0038 ◽

2020 ◽

Vol 9 (7) ◽

pp. 1787-1810 ◽

Cited By ~ 3

Author(s):

Xiao Han ◽

Yongshen Zheng ◽

Siqian Chai ◽

Songhua Chen ◽

Jialiang Xu

Keyword(s):

Nonlinear Optical ◽

Second Harmonic ◽

Low Cost ◽

Laser Pulses ◽

Structural Features ◽

Photon Absorption ◽

Saturable Absorption ◽

Research Attention ◽

Inorganic Hybrid ◽

Quantum Well Structures

AbstractTwo-dimensional (2D) organic-inorganic hybrid perovskites feature characteristics of inherent quantum-well structures and intriguing optoelectronic properties, and have therefore attracted enormous research attention for their optical applications in light emitting, sensing, modulation, and telecommunication devices. The low-cost and solution-processed fabrications as well as alternative organic spacer cations endue 2D hybrid perovskites with higher tunability in optical and photonic applications. In particular, they demonstrate distinguished nonlinear optical characters such as second-harmonic generation (SHG), two-photon absorption (2PA), and saturable absorption (SA) under the excitation of laser pulses. Here, we discuss the construction of the various sorts of 2D hybrid perovskites with different structural features. We have also highlighted some representative properties and applications of these 2D hybrid perovskites in both linear and nonlinear optical regimes.

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