Lowest roughnesses on aspheres

Monday, March 10, 2014

asphericon is successfully concluding a further project to boost its technological leadership in processing highly challenging aspheric optical components. The focus of the company's endeavors lay on establishing a new production technique to realize the lowest roughnesses.

"For us, reducing surface roughnesses on aspheric surfaces is, in addition to reducing surface shape deviations, one of the focuses of our development work," commented CEO Sven R. Kiontke. "In particular, the constantly increasing sensitivity of optical sensors as well as the higher demands in the UV and high-performance laser field mean that surface roughness is becoming a ever more important topic. We have thus improved our machining processes to enable as little scattered light as possible to be created by lower roughnesses. Only in this way can the high demand on optical functionality be ensured," added Kiontke.

As part of the development work, asphericon was able to successfully conclude the first client projects with surface roughnesses of up to 4 angstroms (see figure 1). The information on roughness always relates here to a strict test field of 1x1mm in contrast to the usual 0.2x0.2mm. The optimized production process can be used for most types of glass and various crystals. In a subsequent project, work is currently already being conducted on improved roughnesses for soft materials, such as Ohara S-FPL53 with a Knoop hardness of just 320.

Overall, with this further development, asphericon is managing to make an enormous leap into the vertical range of manufacture as well as round off its own value creation chain in a suitable manner, which now extends from design development and actual manufacturing through to the assembly of optical modules and the subsequent optical characterization.