To improve the surface roughness accuracy of optical glass prism, we can start from the following aspects:

Optimize the processing technology:

Grinding process:

Selection of suitable grinding materials: according to the characteristics of optical glass, select grinding abrasive or grinding powder with appropriate hardness and particle size distribution. For example, for optical glass with higher hardness, grinding materials with slightly higher hardness and uniform particle size should be selected to ensure grinding efficiency and surface quality. The finer the particle size of the abrasive material, the lower the surface roughness after grinding, but the grinding efficiency will also decrease accordingly, so it is necessary to comprehensively consider and select the appropriate particle size range.

Control grinding pressure and speed: It is very important to maintain uniform and moderate grinding pressure and speed during grinding. Too much pressure can easily lead to scratches, pits and other defects on the glass surface, while too little pressure may make the grinding efficiency low and the ideal surface roughness cannot be achieved. If the speed is too fast, the grinding material will have uneven effect on the glass surface; if the speed is too slow, the processing time will be prolonged and the cost will be increased. Generally speaking, it is necessary to determine the best grinding pressure and speed parameters through experiments according to the material and size of glass and the performance of grinding equipment.

Adopt multi-step grinding: carry out multi-step grinding processes such as rough grinding, fine grinding and ultra-fine grinding. Rough grinding is mainly to remove most of the surplus on the glass surface and improve the smoothness of the surface; Fine grinding is to further reduce the surface roughness and make the surface smoother; Ultra-precision grinding is based on fine grinding to achieve higher surface roughness accuracy. After each grinding step, the glass surface should be cleaned and inspected to ensure that the surface quality meets the requirements before the next grinding step.

Polishing process:

Select high-quality polishing materials: such as high-quality polishing pad, polishing solution, etc. The material and hardness of the polishing pad should match the optical glass, so as to ensure that the pressure can be uniformly applied during the polishing process, and to avoid local over-polishing or under-polishing. The chemical composition and concentration of polishing solution will also affect the polishing effect, and it needs to be selected according to the material and surface roughness requirements of glass.

Control polishing time and temperature: too long polishing time may lead to overheating of glass surface, stress and deformation, and affect surface roughness; If the polishing time is too short, the ideal polishing effect cannot be achieved. Therefore, the appropriate polishing time should be determined according to the material and size of glass and the performance of polishing equipment. At the same time, the temperature during polishing should be controlled to avoid the influence of too high temperature on the optical properties and surface quality of glass. The polishing process can be cooled by water cooling or air cooling.

Adopt advanced polishing technology: For example, chemical mechanical polishing (CMP) technology combines the advantages of chemical corrosion and mechanical grinding, which can improve the polishing efficiency and the stability of surface quality while ensuring the accuracy of surface roughness. Ion beam polishing technology uses ion beam to bombard the glass surface to remove tiny bumps and defects on the surface, thus obtaining extremely high surface roughness accuracy.

Select high-precision processing equipment;

Accuracy of machine tool: Choose a machine tool with high positioning accuracy, repetitive positioning accuracy and motion accuracy. For example, the use of CNC machining centers or precision grinding machines can accurately control the trajectory of the cutter or grinding head in the machining process and ensure the machining accuracy of the optical glass prism. The accuracy and rigidity of key parts such as guide rail and screw rod of machine tool will also affect the machining accuracy, so it is necessary to choose the brand and model of machine tool with reliable quality.

Accuracy of testing equipment: It is equipped with high-precision surface roughness testing instruments, such as atomic force microscope (AFM) and interferometer, so as to timely and accurately detect the surface roughness of optical glass prism and provide basis for adjustment and optimization of processing process. The accuracy of the testing equipment is higher than that required for machining, so that tiny defects and errors in the machining process can be effectively detected.

Strictly control the processing environment:

Temperature control: the temperature change of processing environment will affect the dimensional stability and processing accuracy of optical glass. Keep the temperature of the processing workshop constant, generally controlled between 20℃ and 25℃, and the temperature fluctuation range should be as small as possible. In the process of processing, the temperature of optical glass prism is monitored to avoid the surface roughness error caused by temperature change.

Humidity control: Too high humidity will damp the surface of optical glass, which will affect the polishing effect and surface roughness accuracy. Therefore, the humidity of the processing workshop should be controlled between 40% and 60%, and air circulation should be maintained to prevent moisture accumulation.

Dust prevention measures: dust particles in the air will adhere to the surface of optical glass, increasing surface roughness. Therefore, the processing workshop should take effective dust-proof measures, such as installing air purification equipment and using dust-free cloth to keep the processing environment clean.

Improve the skill level of operators;

Training and experience accumulation: provide professional training for operators to familiarize them with the processing technology and equipment operation methods of optical glass prisms, and master the key technologies and precautions in the processing process. At the same time, operators are encouraged to accumulate experience and improve their ability to judge and deal with various problems in the processing.

Implementation of process discipline: operators are required to operate in strict accordance with the processing procedures to ensure that each processing link meets the quality requirements. Establish a strict quality inspection system, supervise and inspect the work of operators, and find and correct illegal operations in time.