scholarly journals Closed-Aperture Z-Scan Analysis for Nonlinear Media with Saturable Absorption and Simultaneous Third- and Fifth-Order Nonlinear Refraction

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Xiangming Liu ◽  
Yasuo Tomita
Keyword(s):  
Optical Materials ◽  
Nonlinear Optical ◽  
Nonlinear Refraction ◽  
Polymer Nanocomposite ◽  
Approximate Expression ◽  
Nanocomposite Films ◽  
Saturable Absorption ◽  
Closed Aperture ◽  
Adomian’S Decomposition Method ◽  
Fifth Order

We present a theory of open- and closed-aperture Gaussian beam Z-scan for nonlinear optical materials with saturable absorption and high-order nonlinear refraction. We show that an approximate expression for a transmitted intensity through the nonlinear optical material is possible by means of the Adomian’s decomposition method and the thin film approximation. The theory is applied to semiconductor CdSe quantum dot-polymer nanocomposite films. It is shown that the theory well explains measured results of open- and closed-aperture transmittances in the Z-scan setup. It is also shown that the nanocomposite film possesses simultaneous third- and fifth-order nonlinear refraction as well as saturable absorption of a homogeneously broadened type.

scholarly journals Large 3rd Order Optical Kerr Nonlinearity in 2D PdSe2 Dichalcogenide Films for Integrated Nonlinear Photonic Chips

2021 ◽  
Author(s):  
David Moss
Keyword(s):  
High Performance ◽  
Nonlinear Optical ◽  
Laser Intensity ◽  
Nonlinear Refraction ◽  
Kerr Nonlinearity ◽  
Photonic Devices ◽  
Closed Aperture ◽  
Third Order ◽  
Limiting Behaviour ◽  
Incident Laser Intensity

<p>As a novel layered noble metal dichalcogenide material, palladium diselenide (PdSe<sub>2</sub>) has attracted wide interest due to its excellent optical and electronic properties. In this work, a strong third-order nonlinear optical response of 2D PdSe<sub>2</sub> films is reported. We conduct both open-aperture (OA) and closed-aperture (CA) Z-scan measurements with a femtosecond pulsed laser at 800 nm to investigate the nonlinear absorption and nonlinear refraction, respectively. In the OA experiment, we observe optical limiting behaviour originating from large two photo absorption (TPA) in the PdSe<sub>2</sub> film of <i>β =</i> 3.26 ×10<sup>-8</sup> m/W. In the CA experiment, we measure a peak-valley response corresponding to a large and negative Kerr nonlinearity of <i>n</i><sub>2</sub> = -1.33×10<sup>-15</sup> m<sup>2</sup>/W – two orders of magnitude larger than bulk silicon. In addition, the variation of <i>n</i><sub>2</sub> as a function of laser intensity is also characterized, with <i>n</i><sub>2</sub> decreasing in magnitude when increasing incident laser intensity, becoming saturated at <i>n</i><sub>2</sub> = -9.96×10<sup>-16</sup> m<sup>2</sup>/W at high intensities. Our results show that the extraordinary third-order nonlinear optical properties of PdSe<sub>2</sub> have strong potential for high-performance nonlinear photonic devices.</p>

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 ◽  
...  
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.

scholarly journals Nonlinear Optical Characteristics of Crystal VioletDye Doped Polystyrene Films by Using Z-Scan Technique

2017 ◽  
Vol 27 (5) ◽  
pp. 83 ◽  
Author(s):  
Mahasin F. Hadi ◽  
Eman Mohi Alwaan ◽  
Wafaa Hameed Abass
Keyword(s):  
Nonlinear Optical ◽  
Laser Light ◽  
Nonlinear Refraction ◽  
Closed Aperture ◽  
Experimental Conditions ◽  
Light Pulses ◽  
Reverse Saturation Absorption ◽  
Self Focusing ◽  
Saturation Absorption ◽  
Doping Ratio

Z-scan technique was employed to study the nonlinear optical properties (nonlinear refractive index and nonlinear absorption coefficient) for crystal violet doped polystyrene films as a function of doping ratio in chloroform solvent. Samples exhibits in closed aperture Z-scan positive nonlinear refraction (self-focusing). While in the open aperture Z-scan gives reverse saturation absorption (RSA) (positive absorption) for all film with different doping ratio making samples candidates for optical limiting devices for protection of sensors and eyes from energetic laser light pulses under the experimental conditions.

Investigation of the Photoluminescence and Nonlinear Optical Properties of Ce2O3–TiO2 Nanocomposites

2021 ◽  
Vol 21 (10) ◽  
pp. 5201-5206
Author(s):  
P. C. Karthika ◽  
K. Mani Rahulan ◽  
Manickam Sasidharan ◽  
G. Vinitha ◽  
R. Seema ◽  
...  
Keyword(s):  
Nonlinear Optical ◽  
Continuous Wave ◽  
Sol Gel ◽  
Nonlinear Refraction ◽  
Saturable Absorption ◽  
Time Resolved ◽  
Nlo Properties ◽  
Visible Spectra ◽  
Sol Gel Process ◽  
Synthesized Materials

This paper reports the photoluminescence and nonlinear optical (NLO) properties of Ce2O3–TiO2 nanocomposites synthesized via sol–gel process with different concentrations of cerium. The physical characterization studies by means of XRD indicated for the successful incorporation of Ce into the lattice of TiO2, while the UV-visible spectra for an absorption edge shift of TiO2 to the higher wavelength side following the Ce addition, and FESEM analysis for the morphology and particles sizes of the synthesized materials. On testing of the photoluminescence properties recorded through time-resolved fluorescence (TCSPC) technique, a decrease in the intensity of TiO2 with that of increased Ce concentration was observed and is due to an escalation in the number of oxygen vacancies. Further, the observation NLO properties for Ce2O3–TiO2 was done by a Z-scan technique of 5ns continuous wave (cw) laser at 532 nm, where the involvement of active mechanisms in the nonlinear refraction and nonlinear absorption are due to the saturable absorption (SA) and nonlinear thermal effects.

scholarly journals Large and negative self-defocusing optical Kerr nonlinearity in Palladium di-Selenide 2D films

2021 ◽  
Author(s):  
David Moss
Keyword(s):  
High Performance ◽  
Nonlinear Optical ◽  
Laser Intensity ◽  
Nonlinear Refraction ◽  
Kerr Nonlinearity ◽  
Optical Response ◽  
Nonlinear Optical Response ◽  
Closed Aperture ◽  
Third Order ◽  
Limiting Behaviour

Abstract We report a large third-order nonlinear optical response of palladium diselenide (PdSe2) films – a two-dimensional (2D) noble metal dichalcogenide material. Both open-aperture (OA) and closed-aperture (CA) Z-scan measurements are performed with a femtosecond pulsed laser at 800 nm to investigate the nonlinear absorption and nonlinear refraction, respectively. In the OA experiment, we observe optical limiting behaviour originating from large two photo absorption (TPA) in the PdSe2 film of β = 3.26 ×10− 8 m/W. In the CA experiment, we measure a peak-valley response corresponding to a large and negative Kerr nonlinearity of n2 = -1.33×10− 15 m2/W – two orders of magnitude larger than bulk silicon. We also characterize the variation of n2 as a function of laser intensity, observing that n2 decreases in magnitude with incident laser intensity, becoming saturated at n2 = -9.96×10− 16 m2/W at high intensities. These results verify the large third-order nonlinear optical response of 2D PdSe2 as well as its strong potential for high performance nonlinear photonic devices.

scholarly journals Transformation from Self-Focusing to Self-Defocusing of Silver Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2485
Author(s):  
Jijuan Jiang ◽  
Yang Jia ◽  
Tong Wu ◽  
Yachen Gao
Keyword(s):  
Silver Nanoparticles ◽  
Refractive Index ◽  
Nonlinear Refraction ◽  
Excitation Intensity ◽  
The Self ◽  
Nanosecond Laser ◽  
Closed Aperture ◽  
Third Order ◽  
Self Focusing ◽  
Fifth Order

The nonlinear refraction of silver nanoparticles (AgNPs) in n-hexane was studied by using the closed-aperture Z-scan technique with a 532 nm nanosecond laser. It was found that, the nonlinear refraction of AgNPs shows the coexistence and transformation from self-focusing to self-defocusing. Specifically, self-focusing occurs at low excitation intensity, self-defocusing occurs at high excitation intensity, and coexistence of self-focusing and self-defocusing occurs at relatively moderate excitation intensity. The experimental results were analysed and discussed in terms of third-order and fifth-order nonlinear refractive effect. Specifically, the self-focusing is caused by the positive third-order nonlinear refraction, the self-defocusing is induced by the negative fifth-order nonlinear refraction, and the transformation from the self-focusing to self-defocusing at medium excitation intensity is caused by the competition of third-order and fifth-order nonlinear refraction. Finally, the third-order refractive index and fifth-order refractive index were obtained.

scholarly journals Large negative n2 and two-photon absorption in 2D PdSe2 films ACS AMI OSF

2020 ◽  
Author(s):  
David Moss
Keyword(s):  
High Performance ◽  
Nonlinear Optical ◽  
Laser Intensity ◽  
Nonlinear Refraction ◽  
Kerr Nonlinearity ◽  
Optical Response ◽  
Nonlinear Optical Response ◽  
Photon Absorption ◽  
Closed Aperture ◽  
Third Order

We report a large third-order nonlinear optical response of palladium diselenide (PdSe2) films – a two-dimensional (2D) noble metal dichalcogenide material. Both open-aperture (OA) and closed-aperture (CA) Z-scan measurements are performed with a femtosecond pulsed laser at 800 nm to investigate the nonlinear absorption and nonlinear refraction, respectively. In the OA experiment, we observe optical limiting behaviour originating from large two photo absorption (TPA) in the PdSe2 film of β = 3.26 ×10-8 m/W. In the CA experiment, we measure a peak-valley response corresponding to a large and negative Kerr nonlinearity of n2 = -1.33×10-15 m2/W – two orders of magnitude larger than bulk silicon. We also characterize the variation of n2 as a function of laser intensity, observing that n2 decreases in magnitude with incident laser intensity, becoming saturated at n2 = -9.96×10-16 m2/W at high intensities. These results verify the large third-order nonlinear optical response of 2D PdSe2 as well as its strong potential for high performance nonlinear photonic devices.

scholarly journals Large 3rd Order Optical Kerr Nonlinearity in 2D PdSe2 Dichalcogenide Films for Integrated Nonlinear Photonic Chips

2021 ◽  
Author(s):  
David Moss
Keyword(s):  
High Performance ◽  
Nonlinear Optical ◽  
Laser Intensity ◽  
Nonlinear Refraction ◽  
Kerr Nonlinearity ◽  
Photonic Devices ◽  
Closed Aperture ◽  
Third Order ◽  
Limiting Behaviour ◽  
Incident Laser Intensity

<p>As a novel layered noble metal dichalcogenide material, palladium diselenide (PdSe<sub>2</sub>) has attracted wide interest due to its excellent optical and electronic properties. In this work, a strong third-order nonlinear optical response of 2D PdSe<sub>2</sub> films is reported. We conduct both open-aperture (OA) and closed-aperture (CA) Z-scan measurements with a femtosecond pulsed laser at 800 nm to investigate the nonlinear absorption and nonlinear refraction, respectively. In the OA experiment, we observe optical limiting behaviour originating from large two photo absorption (TPA) in the PdSe<sub>2</sub> film of <i>β =</i> 3.26 ×10<sup>-8</sup> m/W. In the CA experiment, we measure a peak-valley response corresponding to a large and negative Kerr nonlinearity of <i>n</i><sub>2</sub> = -1.33×10<sup>-15</sup> m<sup>2</sup>/W – two orders of magnitude larger than bulk silicon. In addition, the variation of <i>n</i><sub>2</sub> as a function of laser intensity is also characterized, with <i>n</i><sub>2</sub> decreasing in magnitude when increasing incident laser intensity, becoming saturated at <i>n</i><sub>2</sub> = -9.96×10<sup>-16</sup> m<sup>2</sup>/W at high intensities. Our results show that the extraordinary third-order nonlinear optical properties of PdSe<sub>2</sub> have strong potential for high-performance nonlinear photonic devices.</p>

scholarly journals Ultra-large Optical Kerr Nonlinearity in 2D PdSe2 Dichalcogenide Thin Films for Integrated Nonlinear Photonics

2021 ◽  
Author(s):  
david moss ◽  
jiayang wu
Keyword(s):  
High Performance ◽  
Nonlinear Optical ◽  
Laser Intensity ◽  
Nonlinear Refraction ◽  
Kerr Nonlinearity ◽  
Photonic Devices ◽  
Closed Aperture ◽  
Third Order ◽  
Limiting Behaviour ◽  
Nonlinear Photonics

As a novel layered noble metal dichalcogenide material, palladium diselenide (PdSe2) has attracted wide interest due to its excellent optical and electronic properties. In this work, a strong third-order nonlinear optical response of 2D PdSe2 films is reported. We conduct both open-aperture (OA) and closed-aperture (CA) Z-scan measurements with a femtosecond pulsed laser at 800 nm to investigate the nonlinear absorption and nonlinear refraction, respectively. In the OA experiment, we observe optical limiting behaviour originating from large two photo absorption (TPA) in the PdSe2 film of &beta; = 3.26 &times;10-8 m/W. In the CA experiment, we measure a peak-valley response corresponding to a large and negative Kerr nonlinearity of n2 = -1.33&times;10-15 m2/W &ndash; two orders of magnitude larger than bulk silicon. In addition, the variation of n2 as a function of laser intensity is also characterized, with n2 decreasing in magnitude when increasing incident laser intensity, becoming saturated at n2 = -9.96&times;10-16 m2/W at high intensities. Our results show that the extraordinary third-order nonlinear optical properties of PdSe2 have strong potential for high-performance nonlinear photonic devices. Keywords: 2D materials, PdSe2 films, Z-scan technique, Kerr nonlinearity, nonlinear photonics.

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