Based On Mems Technology, Micro-modeling Of Adaptive Optics Systems And Key Technologies

With the rapid development and the wide application of adaptive optics technology, the traditional large adaptive optics system can no longer meet the need in the fields such as aviation and aerospace, laser weapons, medical high-resolution imaging and laser communication systems. Some adaptive optics systems with low cost, low volume and high performance are expected. The advent of MEMS technology offers the possibility of making that kind of adaptive optic system. With the MEMS technology, the functions of wavefront sensing, reconstruction and correction can even be preformed on a single chip. So, the micro-mechanical adaptive optic system is being more and more promising. In this thesis, the model of a micro-mechanical adaptive optic system was established and some simulations were made. In addition, several key technologies about the micromirror design were explored.Firstly, the Kolmogorov statistical model of the atmospheric turbulence and the wavefront distortion by effects of turbulence were studied. The conclusion was drawn that the wavefront distortion effected by several turbulences could multiply linearly.Secondly, three kinds of wavefront sensing technologies and two kinds of wavefront reconstruction theories were studied and compared, then the Shack-Hartmann wavefront sensing technology and the Zernike-based modal wavefront reconstruction method were selected for the modeling of the micro-mechanical adaptive optics system. After that, the wavefront sensing, reconstruction and correction of the system were simulated and the results were analyzed.Thirdly, two kinds of flexure beams with changeable elastic stiffness were designed and their applications in extending the valid stroke of the micromirror with the electrostatic parallel-plate actuators were analyzed.Finally, the corresponding microfabrication process and layout of four kinds of segmented deformable micromirrors were designed.The results of the simulation and research indicate that the segmented deformable micromirror can effectively correct the distorted wavefront and can increase the Strehl ratio obviously. And by using any kind of these two springs, the valid stroke of the micromirror can be extended definitely.