ABSTRACT :

Nonlinear materials have attracted considerable attention of many
researchers; as they explore their linear and nonlinear optical properties
attempting to develop photonic devices. Such materials must encompass a
high nonlinearity, low absorption, fast response time, large dynamic
range and broadband spectral response. To accomplish the same scientific
achievement, this study focused on investigating some linear and
nonlinear optical properties of specific types of natural dyes extracted
from some fruits at prepared at different conditions. This project aims to
develop nonlinear optical properties archive of the investigated dye
extracts that are available in the Kingdom of Bahrain.
In this study, 52 samples of dye extracts from assortment of fruits
were extracted such as orange, pomegranate, blueberry, cranberry, cherry,
black raisin, tropical almond, avocado, prune, strawberry, mangosteen
and apricot. These samples were arranged in five groups. Most of the
samples were prepared at three different concentrations. pH level has
been changed for some samples at specific concentration by addition of
specific volume of HCl in order to realize the effect of such factor.
Samples absorbance was measured in order to quantify the spectral linear
absorption coefficient (()) and to gain insight on absorption behavior
at range of wavelength from 400-1000 nm. Fluorescence spectra are
recorded. Also, the linear refractive index was measured using the
Refractometer. Under different excitation power level and three different
wavelength (i.e., 488 nm, 514 nm and 633 nm) nonlinear refractive index
(n2) sign and value, nonlinear absorption coefficient, third-order nonlinear
optical susceptibility χ(3) were quantified after fitting raw data obtained
using single beam Z-scan technique. The investigated samples show
C potential capability of them to be used as optical limiters as well as all
optical switching devices.