In many optical applications plane optical elements are needed for deflection or splitting of light. The functionality of these parts is usually reduced to one certain task and manufacturing of them needs a big amount of effort to achieve high precision. A new optical element is presented, which can fulfill different optical functions simultaneously, is simply built and robust. It is based on glass cuboids joined together under a certain angle while introducing the possibility of fine adjusting the angle in the manufacturing process. The basic components can be modified to offer a lot of different applications. A technological process development is presented as well for more efficient machining of these new parts and existing part geometries. Novel manufacturing processes like ultrasonic grinding, ultrafine grinding and diffusion joining are experimentally investigated, since they promise significant improvements compared to conventional methods. Finally, an appropriate process chain is developed.
The production of complex glass components with 2.5D or 3D-structures involves great effort and the need for advanced CNC-technology. Especially the final surface treatment, for generation of transparent surfaces, represents a timeconsuming and costly process. The ultrasonic-assisted grinding procedure is used to generate arbitrary shaped components and freeform-surfaces. The special kinematic principle, containing a high-frequency tool oscillation, enables efficient manufacturing processes. Surfaces produced in this way allow for application of novel smoothing methods, providing considerable advantages compared to classic polishing. It is shown, that manufacturing of transparent glass surfaces with low roughness down to Rq = 10 nm is possible, using an ultra-fine grinding process. By adding a CO2-laser polishing process, roughness can be reduced even further with a very short polishing time.
The fabrication of high-quality optical components involves great effort. Polishing often functions as the final step in a manufacturing chain. To reduce the conventionally time-consuming, complex polishing process with loose grain, an interesting approach with novel resin bond grinding tools is presented for surface smoothing. Various processing-experiments were carried out, regarding different silicate materials such as BK7® and fused silica. Among other results it is shown, that good surface qualities with low roughness down to Ra = 8 nm or Rq = 10 nm can be achieved so far, a quality that already allows speaking of “ultra-fine” grinding. This results in remarkable possibilities to reduce conventional fine-machining procedures with loose abrasives. The fine grinded components can directly be polished to finally smooth the surface and remove remaining defects. Total-processing-times can be strongly reduced, involving significant economic advantages.