Nonlinear absorption coefficient of pulsed laser deposited MgZnO thin film

2015 ◽  
Author(s):  
Arpana Agrawal ◽  
Tanveer A. Dar ◽  
Ravi Solanki ◽  
D. M. Phase ◽  
Pratima Sen
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.


2021 ◽  
Vol 9 (2) ◽  
pp. 46-50
Author(s):  
Muhanad A. Ahmed ◽  
Mohammed F. Mohammed Sabri ◽  
Wathiq R. Abed

In this paper, nanostructured silicon carbide (SiC) thin films are deposited onto glass substrate using pulsed laser deposition technique. Electrical and optical characterizations such as conductivity, resistivity, transmission, Seeback effect, absorption, absorption coefficient, energy band gap, and extinction coefficient as a function of photon energy, and the effect of thin films thickness on transmission are carried out to characterize the prepared samples. Results showed that the prepared SiC thin film is an n-type semiconductor with an indirect bandgap of ~3 eV, 448 nm cutoff wavelength, 3.4395 × 104 cm−1 absorption coefficient and 0.154 extinction coefficient. The surface morphology of the SiC thin films is studied using scanning electron microscope at a substrate temperature of 400 °C and it is found that the grain size of the prepared SiC thin film is about 30 nm. As such, the nano thin films optical and structural characteristics enable the films to be used as gases sensors in many optoelectronic devices such as the environment and ultraviolet photodiode.


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.


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.


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.


2008 ◽  
Vol 22 (18n19) ◽  
pp. 3165-3171 ◽  
Author(s):  
M. H. MAJLES ARA ◽  
Z. DEHGHANI ◽  
S. SAIEVAR IRANIZAD

Nano-particle materials with large optical nonlinearities are in great need for the development of nonlinear optical technology and are being studied intensively in recent years. ZnO nanoparticles have been synthesized by precipitation from zinc acetate in a series of n-alkanols from ethanol to 1-hexanol as a function of temperature. The formation and microstructure of ZnO particles were monitored by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis spectrum and z-scan technique. We studied the optical limiting effect of ZnO nano-particles. Using a CW He - Ne laser at 632.8 nm. The UV-Visible spectrum of this material shows a 373.5 nm peak. Using the UV-Visible, the band gap of this nano-particle is obtained about 3.31 eV. Also the XRD spectroscopy indicates that the structure is wurtzite hexagonal. Average particle size obtained from SEM analysis about 43nm. Furthermore the nonlinear refractive index, n 2, and nonlinear absorption coefficient, β, were measured using close and open aperture z-scan respectively, at peak laser irradiation of 1.743 kW/cm2. Then the nonlinear refraction index of this nano-particle was measured in order of 10-7 (cm2/W) with negative sign and the nonlinear absorption coefficient was obtained in order of 10-3 (cm/W).


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