Applied Physics Research; Vol. 10, No. 3; 2018 ISSN 1916-9639 E-ISSN 1916-9647 Published by Canadian Center of Science and Education 7 Studying the Linear and Nonlinear Optical Properties by Using Z-Scan Technique for CdS Thin Films Prepared by CBD Technique Ahmed S. Jabbar 1 , Sabah I. Abbas 2 & Muneer H. Al-zubaidy 1 1 Department of Physics, College of science, Wasit University, al-kut, Iraq 2 Department of Medical physics, College of sciences, Al-Karkh University, Baghdad, Iraq Correspondence: Ahmed S. Jabbar, Department of Physics, College of science, Wasit University, al-kut, Iraq. Tel: 078-0852-6205, 077-3537-3848. E-mail: ahmsal988@gmail.com Received: February 8, 2018 Accepted: March 14, 2018 Online Published: April 11, 2018 doi:10.5539/apr.v10n3p7 URL: https://doi.org/10.5539/apr.v10n3p7 Abstract CdS films prepared by using CBD technique, linear optical properties tests measured by UV-3000 Nano from OPTIMA, nonlinear properties contained the nonlinear refractive index and nonlinear absorption coefficient by using single light beam source green semiconductor developed laser (SZ- 303 LASER) with material Nd:YVO4+KTP or Aluminum Alloy, and Wavelength Range is (532 nm), Beam Dimension 6 Meter distance Output Laser spot 18 mm ± 2.0 mm. Keywords: nonlinear optical properties, SZ- 303 LASER, CdS, CBD 1. Introduction CdS films prepared by using Chemical Bath Deposition as a preparation technique deposit at different durations started with (30 minutes) and ending in (120 minutes) by adding 30 minutes on every sample. CBD technique is the simplest method (Khallaf, 2009) and doesn't costs, also it gives a diversified thicknesses at every times that deposition time increased. Samples testes to calculate linear and nonlinear properties and that by using (UV-3000 Nano) to linear optical properties and (Z-scan method) for calculate the nonlinear optical properties. Z-scan technique is amongst the simplest and most sensitive of these techniques. The basic Z-scan technique has been described by Sheik-Bahae, Said, and Van Stryland (1989) and Sheik-Bahae et al. (1990), and a brief summary of the theory of the technique is presented here. The most important aspects to be considered for an experimental setup, along with some of the constraints that need to be placed on the design of the setup, will be highlighted (Sheik-Bahae & Hasselbeck, 2000). 2. Theory of Z-Scan Method The z-scan technique operates on the principle of moving the sample by focusing the Gaussian laser beam focused on it (Sheik-Bahae, Said, & Van Stryland, 1989; Sheik-Bahae & Hasselbeck, 2000). The intensity of the laser beam changes through the detector whenever the sample is moved and moved, due to the interaction between the medium and the laser light. A change in the mean means that the sample is experiencing a different laser beam intensity during the sample resulting from the interaction between the material and the intensity of the laser, dependent on the sample position (z) relative to the focus (z = 0). By measuring the transmitted power (the transmittance) through the sample as a function of z-position of the sample, information about the light-matter interaction can be extracted. The two nonlinear interactions that can be determined in this fashion are the sample’s nonlinear index of refraction and nonlinear absorption coefficient (Sheik-Bahae & Hasselbeck, 2000). To detect the nonlinear properties as the absorption coefficient and the nonlinear refractive index, there are two methods, each of which is calculated as one of them depending on the other : (i) The geometry in which a finite aperture is kept before the detector is known as a closed-aperture (CA) Z-scan; (ii) the geometry in which the aperture is removed to focus all the transmitted light into the detector is referred to as an open-aperture (OA) Z-scan (Costela et al., 1996; Hutchings, Sheik-Bahae, Hagan, & Van Stryland, 1992; Chari et al., 1996). The main principle of z- scan technique is based on transforming the phase distortion to amplitude distortions during beam propagation (Sheik-Bahae, Said, & Van Stryland, 1989).