Application Scope and Fabrication Method of Cylindrical Mirror

Time：

2022-12-13

Cylindrical mirror
Cylindrical lens is an aspherical lens, which can effectively reduce spherical aberration and chromatic aberration.
It is divided into flat convex cylindrical lens, flat concave cylindrical lens and cylindrical lens.
It has one-dimensional amplification function. It is mainly used to change the design requirements of imaging size. For example, convert a spot light spot into a line spot, or change the height of the image without changing the image width. It can be applied to linear detector illumination, barcode scanning, holographic illumination, optical information processing, computer, laser emission, etc. Optical cylindrical lenses are also widely used in high power laser systems and synchrotron radiation beams. With the application becoming more and more extensive, the requirements for cylindrical lenses are becoming higher and higher, especially in high-precision testing instruments and devices such as high-power laser resonator and long distance offline interferometer.
The production process of cylindrical mirror mainly includes rough grinding, fine grinding, polishing, centering and edging.
Coarse grinding cylindrical lens
Generally, the rough grinding of cylindrical mirrors with small radius is to glue the square blank to the mould, form a cylinder, and then process the outer circle to obtain the cylindrical surface. Parts with a thickness equal to or greater than the radius of curvature R of the cylindrical surface are generally rough ground into a whole cylinder, and then polished after finishing the fine grinding and polishing.
Conventional cylindrical grinder can be used for rough grinding of cylindrical mirror, but centerless grinder shall be used if the diameter of cylindrical mirror is small.
Generally, when the number of cylindrical mirrors is not large, the four corners of the square blank can be manually ground off on the rough mill first, then the cylinder is installed on the spindle of the instrument lathe, and then the flat iron plate inclined to a certain angle with the horizontal plane is installed on the lathe tool rest to process the outer circle. Coarse grinding of cylindrical mirrors with medium or higher curvature radius can be formed by milling.
Finely ground cylindrical mirror
For the fine grinding of small radius cylindrical mirrors, when the number of products is small, the method of manual plus instrument lathe can still be used. The details are just to replace the fine grinding abrasives. When mass production, the method of upper and lower flat grinding and intermediate clamping separator is generally used. During the fine grinding process, the cylinder should be regularly turned around to avoid grinding into a cone. Another way to fix the separator is to replace the intermediate mandrel with an outer retainer ring.
For cylindrical mirrors with medium radius, after milling and forming, they are often glued to the mould to form a mirror column for fine grinding. Then install the mirror column on the lathe spindle, and then install the mold on the lathe tool holder and add loose abrasive for fine grinding. For concave cylindrical mirrors and large radius cylindrical mirrors that are not suitable for gluing into a cylinder, the mirror plate is usually glued first, and then the corresponding cylindrical mold is used for fine grinding on a special cylindrical machine tool.
Cylindrical mirror polishing
The polishing process is similar to fine grinding. Generally, there is a layer of felt with a thickness of 3-5 mm on the polishing mold, and the length of the polishing mold is about 1/3 of the length of the column.