The Generation of Higher Order Diffraction Beams by Photorefractive Record of Harmonic Optical Field
Norbert Tarjanyi, Ivan Turek
DOI:
Abstract
There are some results of investigation of photorefractive record of interference field created by two planar wave of Ar laser (488 nm) in LiNbO3:Fe presented in this work. Such record behaves as a phase diffraction grating. The time dependence of diffracted beam intensity informs about process of the record creation. To read this record a weak beam of He-Ne laser (632.8 nm) was used. During recording and erasure process of the record, the intensities of the zero and intensities of higher orders on both sides of reading beam were detected. Experimentally obtained time dependences of intensities of diffracted beams were compared with dependences following from diffraction integral integral for harmonic phase grating. Quite small differences between measured and calculated dependences occurred. The differences show that there are some non-linear processes taking place at the record creation.