| Fast steering mirror is a key component,which works between the light source or the receiver and the target.It is used to adjust and stabilize the optical axis or light beam.It has the advantages of small size,compact structure,high accuracy,high bandwidth and high speed.It has been widely used in space laser communication,astronomical telescope adaptive optics,aerial photography image motion compensation,high-precision laser processing and the launching laser system.Developed countries have produced mature products of fast steering mirror in many fields,but it is quite difficult to import this technology.Therefore,this dissertation conducts a research on the fast steering mirror oriented to high-end applications,to provide the product with market competitiveness,and to fill in the blank of domestic related research field.Based on the large optical aperture and large deflection angle fast steering mirror,theoretical analysis,finite element analysis and practical experiments were conducted to intensive study the key technology of fast steering mirror.Each content was described respectively as follows:1.The domestic and foreign FSM products and applications had been investigated in detail.Performances and characteristics of different FSM systems were analyzed and compared.Development tendency,key technology,emphasis and difficulties of FSM systems were summarized.Common structural composition,main performance index,properties of constituent part and the connection between each other were studied and then parameter indexes of FSM system 1 with large optical aperture and FSM system 2 with large deflection angle were proposed.2.Three layout schemes of actuators were compared.Mechanical model and transfer function of FSM system 1 were confirmed.Parameters of actuator were confirmed through inferring the relation function between PZT index and performances of FSM and then the final structure was finished.Statics and dynamics finite element analysis were conducted on FSM system 1 by software Hypermesh?Patran&Nastrsn.After assembling the machined parts,experimental platform was set up to test the static performances and dynamic performances.Test results were compared with theoretical results and simulation results,and then the error was below 8%.Reliability and accuracy of analysis was verified.3.Intensive study of displacement amplifier and flexible hinges was conducted,which were key sections of FSM system 2.First of all,bending of cantilever and stretching of hinges were studied when force was applied on displacement amplifier.Theoretical magnification and function of the loss of displacement were obtained.The impact of flexible supports of different units on performance of FSM system 2.In the end,the optimal result of unit size was confirmed after optimizing the parameters of hinge unit through software Hyperstudy.Improved the one-piece structure of FSM to separate designing,greatly reduced the risk of damage in the course of using and transportation.After the final structure of FSM system 2 was determined,the system was assembled,and the static and dynamic performances of system were tested.The results of theoretical analysis and simulation analysis were proved to be accurate.4.The method of improving mirror surface figure accuracy is studied.Advantages and disadvantages of the scheme of mirror with coating reflective film on backface and the scheme of mirror with coating anti-reflective film was studied and discussed.Bonding strength of adhesives was verified by test.The thermal stress coupling of mirror was reduced through optimizing the structure of bracket,RMS of mirror figure was improved from 1/10? to 1/25?(?=632.8nm). |
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