scholarly journals Влияние лазерного разрушения на нелинейно-оптические свойства core/shell наностержней Au/SiO-=SUB=-2-=/SUB=-

2021 ◽  
Vol 129 (12) ◽  
pp. 1583
Author(s):  
Т.А. Чевычелова ◽  
А.И. Звягин ◽  
О.В. Овчинников ◽  
М.С. Смирнов ◽  
А.С. Перепелица
Keyword(s):  
Silicon Dioxide ◽  
Gold Nanorods ◽  
Nonlinear Optical ◽  
Colloidal Solution ◽  
Second Harmonic ◽  
Nonlinear Refraction ◽  
Core Shell ◽  
Spherical Nanoparticles ◽  
Au Nps ◽  
532 Nm

The mechanisms of nonlinear optical response from ensembles of gold nanorods coated with a silicon dioxide (Au / SiO2 NRs) shell are analyzed. The Z-scan method under the action of 10 ns pulses of the second harmonic of a YAG: Nd3 + laser (532 nm) was used to find dependences characteristic of nonlinear absorption and a negative dynamic lens. It is shown that the bleaching of the colloidal solution, which intensifies with increasing pulse energy, is caused by laser destruction of the Au / SiO2 NRs, which occurs due to melting, which is confirmed by theoretical estimates. Negative nonlinear refraction is attributed to the response from spherical nanoparticles (Au NPs) formed upon laser destruction of NRs.

Nonlinear Optical Properties of Tetrabenzporphyrins

1994 ◽  
Vol 374 ◽  
Author(s):  
Gary L. Wood ◽  
Andrew G. Mott ◽  
Mary J. Miller ◽  
Masato Nakashima ◽  
Joseph F. Roach
Keyword(s):  
Optical Properties ◽  
Cross Section ◽  
Ground State ◽  
Nonlinear Optical ◽  
Laser Light ◽  
Nonlinear Refraction ◽  
Nonlinear Behavior ◽  
Population Redistribution ◽  
Optical Focusing ◽  
532 Nm

AbstractOptical limiting in a solution of tetrabenzporphyrin (TBP) dissolved in tetrahydrofuran (THF) was measured in an f/5 optical focusing arrangement using 532 nm wavelength laser light with a 9 ns pulse duration. The performance of this solution was compared to a variety of other materials. In order to better understand the nonlinear behavior of this material, apertured and unapertured Z-scans were performed. From these measurements it was determined that the excited-state cross section and its ratio to ground-state cross section were large. The nonlinear refraction of this material is made up of contributions from thermal density change and population redistribution. Limiter performance was modeled in an f/64 limiter. The limiter behavior of a slightly modified compound and an additional solvent were measured.

scholarly journals Nonlinear optical response of some Graphene oxide and Graphene fluoride derivatives

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Nikolaos Liaros ◽  
Ioannis Orfanos ◽  
Ioannis Papadakis ◽  
Stelios Couris
Keyword(s):  
Graphene Oxide ◽  
Nonlinear Absorption ◽  
Nonlinear Optical ◽  
Nonlinear Refraction ◽  
Optical Response ◽  
Nonlinear Optical Response ◽  
Third Order ◽  
Nonlinear Properties ◽  
Graphene Derivatives ◽  
532 Nm

AbstractThe nonlinear optical properties of two graphene derivatives, graphene oxide and graphene fluoride, are investigated by means of the Z-scan technique employing 35 ps and 4 ns, visible (532 nm) laser excitation. Both derivatives were found to exhibit significant third-order nonlinear optical response at both excitation regimes, with the nonlinear absorption being relatively stronger and concealing the presence of nonlinear refraction under ns excitation, while ps excitation reveals the presence of both nonlinear absorption and refraction. Both nonlinear properties are of great interest for several photonics, opto-fluidics, opto-electronics and nanotechnology applications.

Tuning optical properties of cadmium thiourea acetate nonlinear optical crystal exploiting organic ligand of L-proline

2019 ◽  
Vol 33 (01) ◽  
pp. 1850424 ◽  
Author(s):  
R. B. Kulkarni ◽  
M. Anis ◽  
S. S. Hussaini ◽  
M. D. Shirsat
Keyword(s):  
Optical Properties ◽  
Nonlinear Optical ◽  
Fourier Transforms ◽  
Second Harmonic ◽  
Structural Parameters ◽  
Nonlinear Refraction ◽  
Organic Ligand ◽  
Infrared Analysis ◽  
Uv Visible ◽  
Shg Efficiency

Modifying optical properties of crystal is very fundamental need for designing various photonic devices, hence in the current investigation, the L-proline (LP) has been firstly doped in cadmium thiourea acetate (CTA) crystal with the aim to optimize the UV–Visible, second harmonic generation (SHG) efficiency, luminescence and third-order nonlinear optical (TONLO) properties of CTA crystal. The pure and doped CTA crystals have been grown by slow solvent evaporation technique at [Formula: see text]C. The structural parameters of grown crystals have been determined using the single crystal X-ray diffraction technique. The incorporation of LP in CTA crystal matrix has been confirmed by Fourier transforms infrared analysis. The UV–Visible studies have been employed within the wavelength range of 200–900 nm to explore the enhancing impact of LP on CTA crystal. The LP doped CTA crystals were subjected to Kurtz–Perry test and Z-scan analysis to identify the nonlinear nature of studied crystals. The SHG efficiency of LP-CTA crystal shows significant increase owing to enhanced charge transfer over the organic ligand of LP. The laser-induced TONLO properties of LP-doped CTA crystal have been determined at 632.8 nm. The nature of nonlinear refraction and absorption has been explored by close and open aperture Z-scan configuration. The magnitude of nonlinear refraction [Formula: see text], absorption coefficient [Formula: see text], cubic susceptibility [Formula: see text] and figure of merit has been determined using the transmittance data. The color-centered luminescence studies have been carried out which established the prominent redshift in peak maxima of emission wavelength of CTA crystal due to doping of LP. Comparative analysis of pure and doped crystal confirmed the dominance of LP doping.

scholarly journals Production of zinc oxide thin films and crystals in different deposition times and investigation of their structural, optical and electronic properties

2019 ◽  
Vol 37 (1) ◽  
pp. 90-99
Author(s):  
Haleh Kangarlou ◽  
Parisa Esmaili
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Electronic Properties ◽  
Density Functional ◽  
Colloidal Solution ◽  
Second Harmonic ◽  
Nonlinear Refraction ◽  
Zno Films ◽  
Full Potential ◽  
Band Gap Structure

AbstractAn aqueous colloidal solution was prepared at 80 °C and pH = 9 from suitable chemical compounds to produce zinc oxide (ZnO) crystals and thin films. The ZnO crystals were grown in the colloidal solution under special conditions. Their micrographs showed ZnO rods with hexagonal structure. The number of the rods, increased over time. The ZnO thin films were produced on glass substrates in the same colloidal solution using the chemical bath deposition (CBD) method in different deposition times. The produced films were post-annealed for about one hour at 400 °C. Crystalline structure, phase transitions and nanostructure of the films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). ZnO wurtzite structure was dominant, and by increasing the deposition time, the films became more crystalline. Nanostructure of the films changed from rod to wire and transformed into pyramid-like structures. Also, morphology of the films changed and re-nucleation ocurred. Optical reflectance was measured in the wavelength of 300 nm to 800 nm with a spectrophotometer. Other optical properties and optical band gaps were calculated using Kramers-Kronig relation on reflectivity curves. Second harmonic generation was calculated by Z-scan technique. Nonlinear refraction and real part of susceptibilities were obtained. Both positive and negative nonlinear refractions appeared in the ZnO films. It is important for the use in optoelectronic devices. Electronic properties were assessed by the full potential linearized augmented plane wave (FP-LAPW) method, within density functional theory (DFT). In this approach, the generalized gradient approximation (GGA) was used for the exchange-correlation potential calculation. The band gap structure and density of states were calculated.

SIZE DEPENDENT SWITCHING FROM REVERSE SATURABLE TO SATURABLE ABSORPTION IN CARBOXYLATE-MODIFIED MICROSPHERES

2011 ◽  
Vol 20 (02) ◽  
pp. 137-143
Author(s):  
MANU VAISHAKH ◽  
S. MATHEW ◽  
V. P. N. NAMPOORI
Keyword(s):  
Optical Properties ◽  
Nonlinear Optical ◽  
Nonlinear Response ◽  
Second Harmonic ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Third Order ◽  
Size Dependent ◽  
The Third ◽  
532 Nm

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.

scholarly journals Nonlinear Optical Characterization of InP@ZnS Core-Shell Colloidal Quantum Dots Using 532 nm, 10 ns Pulses

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1366
Author(s):  
Rashid A. Ganeev ◽  
Andrey I. Zvyagin ◽  
Ivan A. Shuklov ◽  
Maksim G. Spirin ◽  
Oleg V. Ovchinnikov ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Nonlinear Refraction ◽  
Colloidal Quantum Dots ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Core Shell ◽  
Nonlinear Scattering ◽  
532 Nm

InP@ZnS core-shell colloidal quantum dots (CQDs) were synthesized and characterized using the z-scan technique. The nonlinear refraction and nonlinear absorption coefficients (γ = −2 × 10−12 cm2 W−1, β = 4 × 10−8 cm W−1) of these CQDs were determined using 10 ns, 532 nm pulses. The saturable absorption (β = −1.4 × 10−9 cm W−1, Isat = 3.7 × 108 W cm−2) in the 3.5 nm CQDs dominated at small intensities of the probe pulses (I ≤ 7 × 107 W cm−2) followed by reverse saturable absorption at higher laser intensities. We report the optical limiting studies using these CQDs showing the suppression of propagated nanosecond radiation in the intensity range of 8 × 107–2 × 109 W cm−2. The role of nonlinear scattering is considered using off-axis z-scan scheme, which demonstrated the insignificant role of this process along the whole range of used intensities of 532 nm pulses. We discuss the thermal nature of the negative nonlinear refraction in the studied species.

scholarly journals Broadband Nonlinear Optical Response of Nitrogen-Doped Diamond

2021 ◽  
Vol 8 ◽  
Author(s):  
Zhengguo Xiao ◽  
Yu Fang ◽  
Yinglin Song ◽  
Yanchao She ◽  
Changhai Tian ◽  
...  
Keyword(s):  
Nonlinear Optical ◽  
Nonlinear Refraction ◽  
Spectroscopic Properties ◽  
Vibrational Modes ◽  
Nitrogen Doped ◽  
Ultrafast Optical ◽  
Diamond Crystals ◽  
Femtosecond Regime ◽  
The Fourier Transform ◽  
532 Nm

A nitrogen-doped diamond crystal with (111) orientation was synthesized with an NaN3 additive in the FeNi-C system at a pressure of 6.5 GPa and a temperature of 1,310°C, using the temperature gradient growth (TGG) method. Spectroscopic properties such as the absorption spectrum and the Raman spectrum as well as the Fourier transform infrared (FTIR) spectrum were studied. FTIR spectroscopy of the C-N vibrational modes at 1,344 and 1,130 cm−1 suggested a nitrogen content of 310 ppm. Its nonlinear optical (NLO) response was investigated using the Z-scan technique under the femtosecond regime. Due to the presence of nitrogen defects, the synthesized crystal performed large nonlinear absorption under both 800- and 532-nm wavelength excitations. However, intrinsic diamond only experiences nonlinear refraction under these two wavelength excitations. Its broadband NLO properties indicated that nitrogen-doped diamond crystals were suitable for the application of ultrafast optical devices.

Sign in / Sign up

Export Citation Format

Share Document