Conformal Optical System Design Based On Adaptive Optics

The existing infrared guided missiles are all designed with the spherical dome, although this kind of dome,because of its characteristics,have the same size of the aberration in different scan field of view, and the aberration is easy to correction. But there is no help for improving the aerodynamic performance of the missiles. And by improving the ratio of length to diameter the conformal optical design can make the missile flight speed, range, mobility and stealth, ect are improved greatly. Thus will greatly improve combat performance of the missiles.But conformal dome is not spherically symmetric,When scanning the each field of a conformal dome in th seeker, will generate dynamic change of aberration. And this will bring difficulty for designing the aberration correction system. So this article will research and design a aberration correction system based on adaptive optics for correcting the aberration of the conformal dome.Through the analysis of the material and shape parameter of conformal dome, this article Chose the reasonable parameters and established a ZnS dome with the length to diameter ratio of 1. By comparing existing conformal optical correction method, a two-stage optimization system is established. The first level optimization system including to design the inner surface of the conformal dome as Zernike surface, a fixed corrector with binary diffractive surface and a system with two axial moving cylindrical lens. Through the combination of the three Correction scheme, Preliminarily correct the aberration of the conformal dome which I designed. Then established Cassegrain system instead of the ideal lenses as imaging system.The secondary mirror of Cassegrain system was designed as deformable mirrors. Wrote the stochastic parallel gradient descent(SPGD) algorithm with MATLAB, and complete the adaptive optics system through communicating between MATALAB and CodeV as the secondary correction system to correct the residual aberration. Finally realized the automatic analysis of the conformal dome field aberration and real-time correction.After correction to the aberration of the conformal dome in each field by the secondary aberration correction system. The wavefront aberration and Zernike aberration of the system are corrected to a small range. The MTF curve of the system in each scan field of view satisfy the requirement of infrared guidance.