Production method of plane continuous diffraction condensing lens

Abstract

The invention discloses a method for preparing a plane continuous diffractive focus lens, which comprises steps of manufacturing a mask of the plane continuous diffractive focus lens and utilizing a method of reactive ion beam etching to continuously transferring micro-structural patterns. The method utilizes the laser directing writing technique to carry out positional quantitative exposure to photoresist on the surface of a photoresist plate, after development, a continuous diffractive micro-structure is formed on the photoresist layer, then the mask is formed via heating and the like, and further the method utilizes the method of reactive ion beam etching to transfer the micro-structure on the surface of the mask to the surface of a substrate, thereby forming the plane continuous diffractive focus lens. The method has the advantages of high manufacturing precision, short manufacturing period, simple manufacturing process, low manufacturing cost and the like, and is suitable for manufacturing the lightweight and high-performance plane continuous diffractive focus lens. Compared with other manufacturing methods, the laser directing writing is the most advanced method, which can meet the manufacturing requirements of high-precision and high-performance continuous diffractive elements.

Description

technical field [0001] The invention relates to a continuous diffractive optical element, in particular to a method for manufacturing a plane continuous diffractive condensing lens. Background technique [0002] With the development of space technology, miniaturization, light weight, and high performance have gradually become one of the main directions of spacecraft development. The application of diffractive optical elements in optical systems is beneficial to reduce system volume, reduce weight, simplify optical systems and improve imaging quality. Therefore, diffractive optical elements have a good application prospect in the field of space remote sensing. Diffractive optical elements mainly rely on the diffraction microstructure on the lens surface to modulate the light amplitude or phase. The microstructure diffraction surface is usually a curved surface or a plane with a continuously changing phase. For a long time, due to the immaturity of manufacturing technology, ...

AI Technical Summary

Problems solved by technology

However, the diffraction efficiency of the binary optical element is proportional to the number of steps, the more the number of steps, the higher the diffraction efficiency, and it also increases the number of mask making, and requires higher alignment accuracy

Therefore, it is difficult to make the diffraction efficiency of the binary optical element very high, the process is cumbersome, the yield is very low, and the cost is high

With the development of technology, people use diamond cutting method to process infrared continuous diffraction microstructure, but due to the low processing precision, the diffraction efficiency is also very low.

Later, a continuous diffractive microstructure was developed by using the mask moving exposure method. The production accuracy is relatively high, but the types of continuous microstructures are limited, and the process is difficult to control and cannot be popularized.