The Development Of Two-dimensional Lateral Shearing Interferometer, And Aero-optics Applications

In the courses of High-Energy Laser (HEL) coming into being, exporting and laser beam propagation, the quality of the laser beam will be degenerated by the flow. Aero-Optics is a new subject where the interactions between fluid motion and electromagnetic wave are investigated. In the study of the future of the laser beam, the quality of an optical system and the phase correction by an adaptive optical system, it is very important to know the phase distortion of the laser beam under all kinds of aberrations. In order to get the information of the phase distortion, the appropriate sensor of wavefront is chosen and the subject about reconstructing the wavefront is studied. It is try to measure the distortion through the heated jet with low speed by the two dimensions Lateral Shear Interferometer (LSI).Firstly the general principle of lateral shear interferometry is described. The advantage of it that it can measure the Ordered Aberration and the Random Aberration at the same time is discussed. The parameters are designed.Secondly, comparisons have been made in the methods of wavefront reconstruction. The Fourier transform method is put forward to get the difference of the phase basing on one interferogram; the equation is established with the X direction and the Y direction. The way to reconstruct the original wave front in lateral-shearing interferometry is to use the Zernike polynomial to gain upon the measured values.At last the interference patterns about heated jet with low speed were gained in the directions of X, Y under the different values of shift. By means of the above-mentioned method, the original wave front was obtained.