scholarly journals USING Z-SCAN TECHNIQUE TO MEASURE THE NONLINEAR OPTICAL PROPERTIES OF PMMA/ZNO NANOCOMPOSITES

2016 ◽  
Vol 78 (3) ◽  
Author(s):  
Haider Mohammed Shanshool ◽  
Muhammad Yahaya ◽  
Wan Mahmood Mat Yunus ◽  
Ibtisam Yahya Abdullah

The study of nonlinear optical properties of polymer nanocomposites has been given increasing attention due its application in laser, communication and data storage technology. There is a need to enhance the understanding of all photonics technologies. In the current work, PMMA-ZnO nanocomposites as foils and as thin films have been successfully prepared. Casting method and spin coating were used to prepare them respectively. Nanocomposites were prepared by mixing ZnO nanoparticles with polymethyl methacrylate (PMMA) as the polymer matrix. Different contents of ZnO nanoparticles were used as the filler in the nanocomposites. The absorbance spectra of the samples were obtained. The linear absorption coefficient was calculated. The nonlinear refractive index and nonlinear absorption coefficient were investigated using a single beam Z-scan technique. A Q-switched Nd-YAG pulsed laser   (532 nm, 7 ns, 5 Hz) was used as a light source. Both thin film’s and foil’s samples showed peak absorption at 375 nm and increasing absorption with ZnO nanoparticles concentration. The nonlinear refractive index was in the order of 10-11 cm2/W for thin film samples and 10-12 cm2 /W for foil’s samples with a negative sign. In contrast, the nonlinear absorption coefficient is in the order of 10-6 cm/W and 10-7 cm /W for thin film and foil respectively. The figures of merit W and T were calculated in order to evaluate the suitability of the samples as optical switching device .However; they unsatisfied the requirements of optical switching devices but they can be considered as an excellent candidate for optical limiting.

Author(s):  
Imad Al-Deen Hussein Ali Al-Saidi ◽  
Hussein Falih Hussein ◽  
Numan Sleem Hashim

Poly (3 - Hexylthiophene - Co - Thiophene) copolymer was prepared by using the addition polymerization method. The Nonlinear optical properties and the behavior of the optical power limiting of the prepared polymer blend poly (3HT- Co - Th) - PMMA films were studied by using the z - scan technique for different weight ratios of the copolymer poly (3HT- Co - Th). In the present work, a continuous wave (CW) diode - pumped solid - state laser (DPSSL) of wavelengths 532 nm was used for the irradiation of the prepared film samples. The nonlinear optical parameters such as, the nonlinear refractive index (n2), the nonlinear absorption coefficient (β), and the      third - order - nonlinear optical susceptibility (χ (3)) of the polymer blend poly (3HT- Co - Th) - PMMA films were determined for different weight ratios of the copolymer poly (3HT- Co - Th). It is observed that the polymer blend poly (3HT - Co - Th) - PMMA films exhibit saturable absorption (SA) and self - defocusing effects, and this gives an indication that both, the nonlinear refractive index (n2) and the nonlinear absorption coefficient (β), have negative values. The obtained results indicate that the prepared polymer blend poly (3HT - Co - Th) - PMMA films are promising materials and can be considered as suitable materials for different optical and electronic applications.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257808
Author(s):  
Dian Alwani Zainuri ◽  
Mundzir Abdullah ◽  
Muhamad Fikri Zaini ◽  
Hazri Bakhtiar ◽  
Suhana Arshad ◽  
...  

The Ultraviolet-visible (UV-Vis) spectra indicate that anthracenyl chalcones (ACs) have high maximum wavelengths and good transparency windows for optical applications and are suitable for optoelectronic applications owing to their HOMO–LUMO energy gaps (2.93 and 2.76 eV). Different donor substituents on the AC affect their dipole moments and nonlinear optical (NLO) responses. The positive, negative, and neutral electrostatic potential regions of the molecules were identified using molecular electrostatic potential (MEP). The stability of the molecule on account of hyperconjugative interactions and accompanying charge delocalization was analyzed using natural bond orbital (NBO) analysis. Open and closed aperture Z-scans were performed using a continuous-wave frequency-doubled diode-pumped solid-state (DPSS) laser to measure the nonlinear absorption and nonlinear refractive index coefficients, respectively. The valley-to-peak profile of AC indicated a negative nonlinear refractive index coefficient. The obtained single crystals possess reverse saturation absorption due to excited-state absorption. The structural and nonlinear optical properties of the molecules have been discussed, along with the role of anthracene substitution for enhancing the nonlinear optical properties. The calculated third-order susceptibility value was 1.10 x10-4 esu at an intensity of 4.1 kW/cm2, higher than the reported values for related chalcone derivatives. The NLO response for both ACs offers excellent potential in optical switching and limiting applications.


2011 ◽  
Vol 20 (02) ◽  
pp. 183-191 ◽  
Author(s):  
FRYAD Z. HENARI ◽  
ABDULLAH M. ASIRI

We report results from investigations of the nonlinear refractive index and nonlinear absorption coefficient of (2E)-3-[4-(Dimethylamino)phenyl]-1-(2,5-dimethylthiophen-3-yl)prop-2-en-1-one and (2E)-3-(3,4-Dimethoxyphenyl)-1-(2,5-dimethylthiophen-3-yl) prop-2-en-1-one using Z-scan technique with a continuous wave (cw) laser at wavelengths 488 nm and 514 nm. The nonlinear refractive index and nonlinear absorption coefficient of both samples were evaluated. The origin of the nonlinear effects was discussed. Optical limiting based on light induced nonlinear refractive index variation is demonstrated. The limiting thresholds were estimated for both samples. The results suggested that these materials offer promise as candidates for optical limiting and optical devices in the low power regime.


2012 ◽  
Vol 05 ◽  
pp. 277-283 ◽  
Author(s):  
M. H. MAJLES ARA ◽  
Z. DEHGHANI

Titanium dioxide (titania) is a cheap, nontoxic and highly efficient photocatalyst being extensively applied for the degradation of organic pollutants, air purification, water splitting, reduction of nitrogen to ammonia, and optical devices due to its optical behaviors. The third-order nonlinear optical properties of TiO 2/ PS nano-composite were studied by means of single beam transmission technique, using a continuous-wave (CW) He - Ne laser beam with a wavelength of 632.8 nm with three different incident intensities. The magnitude and sign of the third-order nonlinear refractive index ( n 2) and nonlinear absorption (β) of TiO 2/ PS nano-composite were determined by use of both the closed-aperture and opened-aperture z -scan techniques. Z -scan technique, developed by Sheik-Bahae et al., has been used widely in material characterization. A single-beam (also called z -scan method) for measuring the sign and magnitude of nonlinear refraction that has simplicity and very high sensitivity has been reported recently. Optical limiting property of TiO 2/ PS nano-composite is studied. The positive sign obtained for nonlinear refractive index indicated that there is a self-focusing effect in the sample. The nonlinear refractive index was in order of 10-8 (cm2/W) and the nonlinear absorption coefficient was obtained in order of 10-2 (cm/W) with negative sign. The values of nonlinear refractive index and nonlinear absorption coefficient are enhanced by decreasing the intensity.


2021 ◽  
pp. 1-7
Author(s):  
Bassam Abbas ◽  
Mohammad Alshikh Khalil

The Z-scan technique was employed to explore the third-order nonlinear optical properties of disperse red 13 organic chromophore solutions in tetrahydrofuran. A continuous-wave He–Ne laser (632.8 nm) was used as a source of irradiation. The nonlinear absorption and nonlinear refractive index coefficients of this dye were investigated. The results showed that this dye has a good nonlinear response with its real and imaginary quantities of third-order susceptibility. The solutions showed negative nonlinear refraction. The best obtained value of the third-order susceptibility was 6.37 × 10–3 esu at a dye concentration of 3.15 × 10–4 mol/L. Moreover, the nonlinear optical properties were enhanced with higher dye concentrations, and an elevated trend in nonlinear absorption and nonlinear refractive index coefficients was observed. Also, it was found that the reverse saturable absorption was the main mechanism responsible for the two-photon absorption effect in DSR13/THF samples.


2020 ◽  
Vol 38 (3A) ◽  
pp. 440-445
Author(s):  
Zahraa M. AL-Asady ◽  
Ali H. AL-Hamdani

In this research, the diffraction ring patterns scan and single-beam Z-scan techniques were used to measure the nonlinear refractive index (n2) and nonlinear absorption coefficient (β). Nano-composite sample, which consists of zinc oxide nanoparticles (ZnO-NPs), and epoxy resin polymer. The sample was prepared by the casting method. A second harmonic generation Nd: YAG laser, which operates at 532 nm and intensity 3183 W/cm2 was used for the two techniques. Z-scan results showed that values for nonlinear refractive index n2 and nonlinear absorption coefficient β were obtained of 6.59*10-9 cm2/W and 1.75*10-3 cm/W respectively. While results for the D-scan technique showed that the number of rings increases with the increasing of laser power.


2009 ◽  
Vol 18 (04) ◽  
pp. 583-589 ◽  
Author(s):  
YUNDONG ZHANG ◽  
LEI MA ◽  
CHAOBO YANG ◽  
PING YUAN

The nonlinear-optical and optical limiting properties of 2(3), 9(10), 16(17), 23(24) phenoxy-phthalocyanines have been investigated using a 10-ns-pulse laser at 532 nm. The nonlinear absorption coefficient (β) is measured by the single beam Z-scan technique. We have observed low power optical limiting, with low limiting thresholds, based on nonlinear absorption in the sample. These studies indicate that the phthalocyanine material is a potential candidate for low power optical limiting applications.


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