Ion Beam Figuring (IBF) for high Precision Optics becomes affordable

The success of many advanced technologies increasingly depends on the precision of the optical lenses used. Therefore the demand for high precision optical elements in more common devices and instruments is increasing as well. Concurrently the need to make devices smaller and lighter weight is also driving the demand for precision optical elements. Therefore, the use of aspherical glass lenses is growing tremendously and has become the standard for many applications. So far most methods for manufacturing aspherical glass surfaces use grinding and polishing. Very sophisticated methods such as Ion Beam Figuring have not been used for common precision optics. The reasons for this might be perceptions of high costs, doubt about the ablation rate and limited knowledge about the technique within the optical industry. Now Asphericon has set up its first ion beam correction system for precision aspherical optics (asphericon ION-Finish). This presentation will show how the ion beam technology has matured and become affordable enough for common precision applications. In some examples we will show how ion beam systems are used to correct aspheres to precisions of better than lambda/60 rms (10nm). Together with a flexible measurement technique, the manufacturing of aspherical glass lenses becomes very fast and cost-efficient. Furthermore, advantages and disadvantages will be discussed. In connection with that the required quality of the pre-polishing will be addressed too. Finally it will be shown how fast the correction process can be and how flexibly the size of the tool can be changed.