Solar Dual-conjugate Adaptive Optical System Of Master Thesis

The turbulence generated by the irregular motion of the atmosphere will have an effect on the front of the light wave.Therefore,the field angle and resolution of the telescope are difficult to achieve the ideal value.In order to improve the performance of the telescope,adaptive optics came into being.It uses detection,wavefront restoration and real-time correction method,will correct the distortion of the light wave that was created by the atmospheric turbulence.In order to solve the problem that the field of view of the traditional adaptive optics system is too small,the idea that divides the atmosphere turbulence into several layers and then correct each layer individually proposed by American Baker,this idea evolved into multi-layer conjugate adaptive optics.The deformable mirror is the core of the adaptive system,which corrects the distorted light wave directly.Scholars at home and abroad are doing research on deformation mirror,China has successfully manufactured a number of prototypes.At present,the development of deformation mirror encountered a problem: Cannot let the deformation mirror have a great number of correction units and a greater correction stroke at the same time.For example,micro electro mechanical system deformation mirror is manufactured by integrated manufacturing,it can build a large number of correction units in a small field,but its correction stroke can only reach the micron level,which means that if the distortion of light is too huge,its Correction effect will be limited.Based on this problem,this paper proposes a combination scheme of the deformable mirror,double the correction stroke by using two deformable mirrors face to face.Or double the number of correction units by letting the two deformable mirrors into a 90 degree.Then we introduced the principle and structure of the two kinds of combinational deformable mirrors.In dual-conjugate adaptive optics system,a combinational deformable mirror is added to increase the number of correction units.In order not to increase the complexity of the system,based on the characteristics of atmospheric turbulence and the comparison of the correction effect,the combinational deformation mirror only replaces the deformable mirror which conjugates to the low turbulence in the original system.In the different models at home and abroad,find out the best conjugate height to make the dual-conjugate system owns the largest isoplanatic angle through simulation and calculation,and determine the thickness of each layer.Then make comparison between the system using combinational deformation mirror and the system using ordinary deformable mirror.The results show that the combined deformable mirror can improve the Strehl ratio of the system.At the same time,we can constitute different kinds of combinational deformable mirrors by using different kinds of deformation mirrors,they have different effect in improving the Stellier ratio of the system,and find the most cost-effective design.The structure of the combinational deformable mirror is simple and the device used is also ready-made.It will not make strict demand to the manufacturing process,and can reduce the cost of the system.With the improvement of the manufacturing process of the deformable mirror,this design can also be applied to the new deformation mirror to improve the performance of correction.