Study of nonlinear optical properties of olive oil

number: 
2079
إنجليزية
Degree: 
Author: 
Aqeel Salah Fadhil Al-Moathen
Supervisor: 
Dr. Anwaar A. Al-Dergazly
Dr.Ziad T.Al-Dahan
year: 
2009
Abstract:

This project introduces a prospective material for photonic laser applications. The material is olive oil which is classified as organic compound, having a good nonlinear optical properties candidate to be used in photonic applications. Many organic compounds that olive oil is contained, phospholipids, cholesterol, glycolipids, fatty acids compound which are able to behave as lyotropic liquid crystal. So, these compounds are characterized by wide photonic applications. A high purity sample of olive oil has been subjected to spectrophotometer to determine the absorption spectra. Then, the nonlinear optical properties represented by nonlinear refractive index and nonlinear absorption coefficient are determined using a highly sensitive method known as z-scan technique. z-Scan experiment was performed using a CW Nd:YAG and Nd:YVO4 lasers in two parts. The first part has been done using a closed aperture placed in front of the detector to measure the nonlinear refractive index at two wavelengths (1064nm and 532nm) and versus incident powers at 1064nm. For 1064nm wavelength, the average nonlinear refractive index is found to have n2,average=3.99×10-6W/cm2. For 532nm wavelength, the nonlinear refractive index is found to have n2=2.45×10-7W/cm2. The second part was done using an open aperture to measure the nonlinear absorption coefficient at two wavelengths (1064nm and 532nm) for different incident powers at 1064nm. For 1064nm wavelength the average nonlinear absorption coefficient is found to have ßaverage=-0.0017 m/W. For 532nm wavelength, the nonlinear absorption coefficient is found to have ß=-7.26×10-4 m/W. Simulation program to generate third harmonic wave using olive oil has been built using MATLAB program. THG intensity has been determined at two cases of sample thicknesses 1mm and 10mm. The minimum threshold incident intensity to obtain THG intensity are equal I.=7530 mW/cm2 at L=1mm and I.= 6220 mW/cm2 at L=10mm. The possibility of generation of third harmonic in olive oil inside the cuvette has been experimented using different powers (90-130) mW of CW Nd:YAG laser. The signal of third harmonic generation has been detected using UV-340 Light Meter.