Study Of The Nonlinear Optical Properties In ZnTe And InN Semiconductors

The nonlinear optical properties of semiconductors were intensively used in the opto-electronic devices, such as all-optical switches, optical limiters and waveguide formation etc. The investigation of nonlinear optical materials is a hot topic in theoretical and experimental research at all times. Therefore the study of nonlinear optical characteristic of semiconductor is of very important and has practical significance.As a sensitive and simple technique, Z-scan is widely applied in the investigation of the nonlinear optical media. Firstly, we review the basic third-order nonlinear optical processes in media. Then we also introduce the principles of Z-scan technique, together with the brief description of the instruments and apparatus. The main part of this thesis on the study of optical nonlinearities in ZnTe and InN semiconductors using Z-scan technique with femtosecond laser pulses.By performing the single-beam Z-scan with femtosecond laser pulses on (110), (111) and (100) oriented ZnTe crystals, we present the experimental evidence of a new kind of Kerr-like nonlinearity induced via terahertz (THz) generation and the linear EO effect in the media. In addition, we have proposed a model, taking into account the Kerr-like...