Nonlinear properties and optical limiting of olive oil by using z-scan technique

A simplified and sensitive experimental technique named z-scan has been used in this work, to study the optical nonlinearity and optical limiting of olive oil. Olive oil is classified as organic compounds which have a good nonlinear optical properties candidate to be used in photonic applications. A high purity sample of olive oil has been subjected to spectrophotometer to determine the transmission spectrum using UV-VIS spectrophotometer. The nonlinear optical properties represented by nonlinear refractive index and nonlinear absorption coefficient are determined by using a CW of 532 nm in two parts. The first part has been done using a closed aperture (with two different diameter 1 mm and 2 mm) placed in front of the detector to measure the nonlinear refractive index which exhibits negative refractive index (defocusing). Second part was done using an open aperture to measure the nonlinear absorption coefficient, where the samples exhibit two photon absorption behavior under the experimental conditions. Real and imaginary parts of the third-order optical nonlinearity, χ⁽³⁾ were evaluated. The third-order nonlinearity of olive oil is dominated by nonlinear absorption, which leads to strong optical limiting of the laser.