Polishing Process of Optical Glass Prisms

Optical glass prisms have a wide range of applications in the field of optics. From microscopes to telescopes and cameras, the processing quality of optical prisms directly affects their optical performance. Among these processing techniques, polishing is a crucial step.

Polishing Principle of Optical Glass Prisms 

Polishing of optical glass prism has always been a complex process influenced by multiple factors. Optical glass polishing is not just a simple physical grinding process. The polishing mechanism is a comprehensive process that combines physical and chemical actions. During polishing, the surface of the optical glass undergoes chemical corrosion and physical abrasion, which work together to gradually smooth the glass surface.

Factors affecting the polishing of optical glass prisms influence the surface quality and polishing speed in the polishing process. The type of optical glass and polishing liquid plays a crucial role. For instance, certain brands of optical glass exhibit different chemical properties, affecting the chemical reactions of polishing liquids during the polishing process. Thus, for the polishing of optical glass prisms, suitable polishing conditions must be selected for different types of optical glass to ensure the optical performance of the prisms.

Cold Processing Steps of Optical Glass Prisms

During the processing of optical glass prisms, cold processing is an important phase. It includes several steps from rough processing to fine polishing. Here are the main steps:

Milling Stage

Milling is the first step in the cold processing of optical glass prisms. This step mainly removes irregular bubbles, impurities, and uneven parts on the glass surface. Through milling, the surface of the optical glass prisms gradually takes shape. The thickness removed in this process is generally between 0.05 to 0.08 millimeters. Milling not only shapes the prisms but also lays the foundation for subsequent fine grinding and polishing.

Fine Grinding Stage

Fine grinding is the second process in the cold processing of optical glass prisms. In the fine grinding stage, the damage layer created during the milling process is thoroughly removed, ensuring that the curvature radius (R value) of the optical glass prisms meets the design requirements. The accuracy of fine grinding is crucial for subsequent polishing steps, as any slight error can affect the final optical performance.

Polishing Stage

Polishing is a key step in the processing of optical glass prisms. The polishing process further reduces the roughness of the prism surface after fine grinding, achieving the required optical quality. This step affects not only the appearance of the prisms but also determines their final optical performance. By selecting the appropriate polishing powder and polishing liquid, surface defects can be effectively reduced, improving the transparency and optical imaging quality of the optical glass prisms.

Cleaning and Subsequent Procedures

After polishing, optical glass prisms need to be cleaned to remove any residual polishing powder from the surface. This step is crucial as any residual material can affect subsequent processing and imaging performance of the optical glass prisms.

Next, the prisms need to undergo edge grinding to adjust the outer diameter of the glass prisms to the specified size. Depending on the application requirements, optical glass prisms may also need coating treatments to enhance the transmission or reflection effects within a specific wavelength range. In some cases, ink coating might be applied to reduce reflection effects.