1. Department of Physics, Science and Research Branch, Islamic Azad University, Fars, 73715-181, Iran.
2. Young Researchers Club, Science and Research Branch, Islamic Azad University, Fars, Iran.
3. Department of Physics, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran.
4. Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei, 116, Taiwan, ROC.