A brief introduction: optical prism manufacturing process

Prisms are solid glass optics that have been frosted and polished into geometrically and optically distinct shapes. The Angle, position, and number of optical flat crystals help define the type and function.

In order to be able to be used successfully in most applications, the manufacturing of prisms must meet very strict tolerances and precision, so the manufacturing requirements for prisms are also very strict, due to the variation in shape, size and the number of the most important reflectors, large-scale automated processes are completely unfeasible for prism manufacturing. In addition, most high-precision prisms tend to be manufactured in small quantities, meaning that automated processes are not necessary, so let's look at how optical prisms are manufactured.

First, a piece of glass (called a "blank glass") is obtained that meets a specific grade and type of glass. This glass is then sanded, or a metal diamond grinding wheel is used to produce a near-finished product. Most of the glass will be removed from this stage, creating a flat but still rough surface. At this point, the size of the forthcoming prism is very close to the required specification. Next, it is a fine grinding process to remove the subsurface cracks of the surface; This stage is called grinding. The scratches left over from this stage will be removed in the second stage. After finishing, the glass surface should appear cloudy and opaque. During the first two stages, the surface of the prism must be wet in order to speed up glass removal and prevent the glass itself from overheating.

The third stage consists of polishing the prism to the required precision according to the specifications. In this stage, the glass is rubbed against a polyurethane polisher wetted with a "grinding paste", an optically polishing compound that usually contains a mixture of water and pumice or cerium oxide. The exact time of the polishing stage is very dependent on the required mirror specifications. Once you finish polishing, you can start chamfering. In this fourth stage, the edge of the prism will pass through a rotating diamond slab, slightly dulling the sharp edges formed in the above steps. After the chamfering, the finished prism is cleaned, inspected (both manually and automatically), and, if necessary, retroactive (AR) and/or metal reflection coating to further help improve overall transmittance and/or reflectivity. Although the process requires more active participation and may require more cycling or manipulation due to the number of reflective surfaces on the prism, generating, smoothing. Throughout the process of manufacturing a prism, each mirror in progress needs to be constantly adjusted and fixed.