Manufacturing of high-precision aspheres

Distortion of removal function based on the local asphericity of aspheric surface and the viscoelasticity of polishing tool in computer-controlled optical surfacing

“…the misfit of the polishing tool and aspheric surface, which causes an irregular distribution of polishing pressure in the contact region, resulting in the distortion of the removal function, and then influences the producing efficiency and accuracy of the aspheric surface. [15][16][17][18][19][20][21] Therefore, it is important to analyze the primary cause of the misfit and the distortion rule of removal function in aspheric polishing, which provides a theoretical guidance for CCOS process optimization and promotes the efficiency and precision manufacturing technique of aspheric surface.…”

“…Kim et al [17][18][19] designed optimal tools that provide largescale compliance to overcome the shape misfit between tool and surface, resulting in a satisfactory performance of tool influence function (TIF) stability. Birnbaum et al 20 indicated that at every radial position of polishing tool there is a different distribution of polishing pressure in the contact region, which is the main reason for the difficulty in maintaining the shape of the ground aspheric lens in polishing. Song et al 21 have analyzed the misfit between the tool and the off-axis aspheric surface in the process of smoothing the grinding ripple with the rigid bonnet tool of Zeeko, and pointed out that the optimizations of polishing path, tool size, and the abrasive powder size can greatly reduce the influence of the misfit between tool and surface.…”

“…Birnbaum et al. 20 indicated that at every radial position of polishing tool there is a different distribution of polishing pressure in the contact region, which is the main reason for the difficulty in maintaining the shape of the ground aspheric lens in polishing. Song et al.…”

Impact of pad material on stability of tool influnce function in CCOS

“…However, there is a wildly recognized challenge in this technology, i.e., the instability of TIF, which causes by some factors, such as the distortion of tool surface, the variety of tool rigidity. In CCOS, the unstable TIF will lead to the uncertainty in the material removal, and reduce the fabricating precision and efficiency of optical components [1][2][3][4].…”