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

Photonics ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 413
Author(s):  
Edappadikkunnummal Shiju ◽  
Kaniyarakkal Sharafudeen ◽  
T. M. Remya ◽  
N. K. Siji Narendran ◽  
Palengara Sudheesh ◽  
...  

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.

2018 ◽  
Vol 190 ◽  
pp. 04016
Author(s):  
Andrey I. Zvyagin ◽  
Aleksey S. Perepelitsa ◽  
Mariya S. Lavlinskaya ◽  
Oleg V. Ovchinnikov ◽  
Mikhail S. Smirnov ◽  
...  

We study the features of the nonlinear optical response of silver nanoparticles (Ag NPs) of spherical and triangular shapes synthesized using a citrate-borohydride approach and their mixtures with methylene blue (MB+). The Z-scans at the wavelengths of 532 nm using 10 ns pulses were used to analyze the nonlinear optical absorption of MB+ solutions, Ag NPs of different morphology, particularly, the concurrence of saturable and reverse saturable absorption in the solution of triangular Ag NP and MB+. We show the significant contribution to the increasing in the normalized transmittance accomplished by photochemical degradation of the non-spherical Ag NPs (extinction maximum of 600 nm) and transformation into the spherical ones (extinction maximum of 400 nm). The nonlinear light scattering is also analyzed, which showed the contribution to the variation of the sample transmission when it approaches the focal plane. It is shown that the nonlinear optical response is not additive in the mixture of Ag NPs and MB+. The increasing of the nonlinear absorption is probably due to both a change in the population of the triplet states of the dye and the efficiency of photochemical degradation of NPs in the presence of MB+.


2012 ◽  
Vol 16 (01) ◽  
pp. 140-148 ◽  
Author(s):  
Syed Hamad ◽  
Surya P. Tewari ◽  
L. Giribabu ◽  
S. Venugopal Rao

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.


Nanophotonics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1787-1810 ◽  
Author(s):  
Xiao Han ◽  
Yongshen Zheng ◽  
Siqian Chai ◽  
Songhua Chen ◽  
Jialiang Xu

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.


2015 ◽  
Vol 24 (02) ◽  
pp. 1550020 ◽  
Author(s):  
S. Mathew ◽  
Manu Vaishak ◽  
Boni Samuel ◽  
T. M. Libish ◽  
P. Radhakrishnan ◽  
...  

Nanostructured zinc sulfide ( ZnS ) thin films were synthesized in polyvinyl alcohol matrix by chemical bath deposition and self-assembly techniques. ZnS nanostructured thin films show second harmonic generation (SHG) under irradiation with a pico-second Nd :YAG laser system and the second harmonic intensity is higher for self-assembled nanotree like structured ZnS thin film in comparison with that from chemical bath deposited thin film. Under nanosecond laser pulses, thin films possess good saturable absorption behavior. The optical bandgap and visible luminescence also get enhanced.


2011 ◽  
Vol 20 (02) ◽  
pp. 137-143
Author(s):  
MANU VAISHAKH ◽  
S. MATHEW ◽  
V. P. N. NAMPOORI

The third order nonlinear optical properties of two different sized carboxylate-modified microspheres are investigated at different pump powers. The nonlinear absorption (NLA) is measured at 532 nm using 10 Hz, 7 ns pulses from the second harmonic generated from a Q-switched Nd -YAG laser in an open aperture Z-scan setup. The nonlinear response is size-dependent, and switching from reverse saturable absorption (RSA) to saturable absorption (SA) is observed as the size increases.


2018 ◽  
Vol 27 (01) ◽  
pp. 1850001
Author(s):  
Feng Wu ◽  
Shunlong Zhao ◽  
Siwen Zhang ◽  
Jiang Lv

The nonlinear optical (NLO) properties of P3HT in orthodichlorobenzene were investigated at 532[Formula: see text]nm by Z-scan technique in the nanosecond domain. The nonlinear refraction of P3HT solution is up to an order of 10[Formula: see text][Formula: see text]esu and changes the sign from positive to negative with an increase in the input intensity. The reverse saturable absorption of the P3HT solution was observed in the intensity range of the measurements and their nonlinear absorption coefficient reaches an order of 102[Formula: see text]cm/GW. The strong optical nonlinearity perhaps allows them to be widely applied in the photoelectric field.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Sandeep Kumar Maurya ◽  
Anuradha Rout ◽  
Rashid A. Ganeev ◽  
Chunlei Guo

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.


2020 ◽  
Vol 128 (9) ◽  
pp. 1380
Author(s):  
А.П. Русинов ◽  
М.Г. Кучеренко

By continuous-pump Z-scanning, the nonlinear light absorption of aqueous and alcohol solutions of methylene blue was studied. It was shown that the mechanisms of optical nonlinearity of these solutions vary depending on the dye concentration and type of solvent. The dependence of the amplitude of nonlinear absorption of dye molecules on the concentration and sign of the surface charge of gold and silver nanoparticles in solution is revealed. Mathematical models of optical nonlinearity for concentrated and diluted solutions of dye molecules are considered; in the latter case, the influence of plasmon nanoparticles on the nonlinear optical characteristics of methylene blue solutions is taken into account


2018 ◽  
Vol 768 ◽  
pp. 239-245
Author(s):  
Qiang Li ◽  
Wei Ying Liu ◽  
Guo Yin Sun

An inserted type Ag/TeO2-SiO2composite gel glass was prepared through silver nanoparticles embedded in TeO2-SiO2composite gel. The silver nanoparticles were prepared previously by ascorbic acid deoxygenates AgNO3solution and mixed into TeO2-SiO2composite sol which was prepared in aqueous system using TeO2and tetraethoxysilane as precursors, and then the inserted type Ag/TeO2-SiO2composite gel glass was produced through sol aging and molding. The silver nanoparticles which dispersed in the TeO2-SiO2gel substrate made the composite glass having excellent nonlinear optical properties. The nonlinear optical parameters was tested by Z-scan technique using 15 ps laser pulses at the wavelength of 532 nm. The surface morphology was characterized by SEM. The results identified that spherical Ag nanoparticles with the size about 50-100 nm dispersed in the TeO2-SiO2gel. In the Ag/TeO2-SiO2material, the doped structure and the trigonal bipyramid structure of TeO2was the important factor for the excellent nonlinear optical performance.


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