The Nonlinear Absorption Coefficient of a Strong Electromagnetic Wave Caused by Confined Electrons in Quantum Wells

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.

Download Full-text

NONLINEAR-OPTICAL AND OPTICAL LIMITING PROPERTIES OF PHENOXY-PHTHALOCYANINES STUDIED USING THE Z-SCAN TECHNIQUE

Journal of Nonlinear Optical Physics & Materials ◽

10.1142/s0218863509004907 ◽

2009 ◽

Vol 18 (04) ◽

pp. 583-589 ◽

Cited By ~ 13

Author(s):

YUNDONG ZHANG ◽

LEI MA ◽

CHAOBO YANG ◽

PING YUAN

Keyword(s):

Absorption Coefficient ◽

Low Power ◽

Pulse Laser ◽

Nonlinear Absorption ◽

Nonlinear Optical ◽

Optical Limiting ◽

Nonlinear Absorption Coefficient ◽

Potential Candidate ◽

Single Beam ◽

532 Nm

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.

Download Full-text

MEASUREMENT OF NONLINEAR RESPONSES AND OPTICAL LIMITING BEHAVIOR OF TIO2/PS NANO-COMPOSITE BY SINGLE BEAM TECHNIQUE WITH DIFFERENT INCIDENT INTENSITIES

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194512002139 ◽

2012 ◽

Vol 05 ◽

pp. 277-283 ◽

Cited By ~ 1

Author(s):

M. H. MAJLES ARA ◽

Z. DEHGHANI

Keyword(s):

Refractive Index ◽

Absorption Coefficient ◽

Nonlinear Absorption ◽

Nonlinear Refractive Index ◽

Optical Limiting ◽

Nonlinear Absorption Coefficient ◽

Third Order ◽

Nano Composite ◽

Single Beam ◽

The Third

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.

Download Full-text

SYNTHESIS, CHARACTERIZATION AND SINGLE-BEAM Z-SCAN MEASUREMENT OF THE THIRD-ORDER OPTICAL NONLINEARITIES OF ZnO NANO-PARTICLES

International Journal of Modern Physics B ◽

10.1142/s0217979208048061 ◽

2008 ◽

Vol 22 (18n19) ◽

pp. 3165-3171 ◽

Cited By ~ 16

Author(s):

M. H. MAJLES ARA ◽

Z. DEHGHANI ◽

S. SAIEVAR IRANIZAD

Keyword(s):

Absorption Coefficient ◽

Nonlinear Absorption ◽

Nonlinear Refraction ◽

Average Particle Size ◽

Nonlinear Absorption Coefficient ◽

Nano Particles ◽

Average Particle ◽

Optical Nonlinearities ◽

Nano Particle ◽

Uv Visible

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).

Download Full-text