Infrared Diffractive Optical Elements Of The Diamond Turning Technology Research

Due to its unique dispersive and environment temperature characteristics, small size as well as reduced weight, diffractive optical element (DOES, e.g. Binary optical elements) can offer optical designer more freedom in design and more materials to select . Currently, most of the IR elements made of the materials such as Germanium, Zinc selenide/sulphide for chromatic aberration correction and athermalization purpose are processed with diamond machine. Although many organizations have carried out some research in DOES in this nation, fewer applications are found in the infrared spectrum with Single-point diamond turning. Even some of the organizations have made some progress in this field, but they are still in lab testing phase and far away from batch production.In this paper, the previous work of the others is summarized, and the development trend and status of DOES technology in domestic and overseas are introduced, the fundamentals of DOES and its fabrication technology are overviewed. Some Exploration, analysis and discussion are made on machining parameters used in diamond turning process and its impact on the element performance. A conceptual experiment is carried out on machining hybrid optical lens used in Infrared imaging optics with diamond cutting technique, the lens is a medium wave IR 3-5 u m aspheric element. Measurement results indicate that its surface roughness is better than 5 nm Ra, and the error between real "hybrid" transfer function and its theoretical value is less than 10%.The work of this paper will standardize the fabrication procedures in processing DOES with diamond cutting technique and set a solid process foundation for the application of DOES.