Research On Hybrid Diffractive-refractive Double-grisms Scanning Technology

By rotating coaxial double-prisms independently, rotating double-prisms scanning technology can change the direction of the beam, realize the wide angle rotating and scanning. In the field of infrared,target aiming and tracking etc, double-prisms have a widely application prospect. But the prisms has aberration, limit the application of rotating-double-prisms. So in this paper we use diffractive optical element combined with prism, and constitute a hybrid optical element, to eliminate the aberration.First of all, according to the imaging theory of refraction element and diffraction element, decide to use the angle aberration method to design the parameters of prism and grating to eliminate the angle aberration.Then, by using the ray tracing method, calculate the vector equation of the emit ray when the media surface is refractive surface or diffractive surface. Build the mathematical model of rotating double-prisms and rotating double-grisms. According to the vector equation of the emit ray, deduce the mathematical equation of rotating double-prisms and rotating double-grisms. Reveal the relationship between the beam scanning model and the parameters of the prism and parameters of the grating. Put forward to use altitude angle and azimuth angle to express the direction of the exit ray.Finally, in the case of mid-infrared wave band ? m5~3 ??, establish the parameter of the prism and the grating. According to the the mathematical equation of rotating double-prisms and rotating double-grisms, use the altitude angle and the azimuth angle to express the exit rays of different wavelengths. Analyze the angle aberration change of rotating double-prisms and double-grisms verified by MATLAB, and analyze the aberration change of rotating double-prisms and double-grisms verified by ZEMAX.