Study the non-linear effects by focusing the high power laser

Summary form only given. Plasma is a nonlinear optical phenomenon. Non-linear situation distinguished in plasma, when a single electron and ions interact with two or more photons. Previous work demonstrated the creation of plasma by different technique. Here, we are going to investigate the behaviour of laser produced plasma. We developed and tested a Langmuir probe made by tungsten (W) wire, suitable for measurement in lab environment. The parameters, such as electron and ion density, electron temperature, and plasma and floating potential are measured by using Langmuir probe. Data acquisition and calculation of plasma parameters are controlled by a personal computer. In order to achieve plasma we used a fundamental study by diagnosing the plasma induced by focusing a Q-switched Nd:YAG laser. The formation of plasma was visualized by using a CCD video camera and interfaced to the personal computer. In order to understand the processes occurring in plasmas, it is necessary to be able to make accurate, spatial measurements of plasma parameters. Thus, Langmuir probe is still one of the most natural approaches to diagnose the parameters of pulsed plasma, especially for the plasma density because the Langmuir probe has to be inserted into the plasma to directly sense the particle flux, it may cause local perturbation of the plasma. The nature of the perturbation depends on the potential of the probe and the electric current drawn by it.