Study of the Nonlinear Optical Properties of Lithium Triborate Crystal by Using Z-Scan Technique

In this experimental work, a study (by using a high sensitive method known as Z-Scan technique) of the nonlinear optical properties for Lithium Triborate crystal (The boronoxygen compound LiB3O5 is recognized as a new Nonlinear Optical crystal). Z-scan experiment was performed using Nd-Yag laser at 532 and 1064 nm with the power output of 40 and 25 mW, in two parts. The first part was done using a closed-aperture placed in front of the detector to measure the nonlinear refractive index. In the second part, the aperture in front the detector was removed (open aperture) to measure the nonlinear absorption coefficient. The experimental results for closed aperture show that the Lithium Triborate crystal exhibits positive refractive index (self-focusing). For open aperture z-scan the results show that the crystal exhibited saturation absorption.