A new approach to laser polishing and form correction of optical components

Harold Kessler,Roelene Botha,Carsten Ziolek,O Fähnle,A Vasdekis

doi:10.1051/epjconf/201921509001

Harold Kessler, Roelene Botha + Show 3 more

Open Access

https://doi.org/10.1051/epjconf/201921509001

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Abstract

The increasing variety of optical components and materials, combined with stricter surface tolerance requirements, necessitate refining existing polishing processes and developing innovative new polishing solutions and metrology technologies. A fast, reproducible laser polishing process would offer considerable economic benefits over conventional mechanical polishing processes and interest a broad variety of optics manufacturers. In this work, a holistic approach is taken to address the various aspects of glass polishing and form correction via a novel laser polishing system design, the use of a measurement strategy that can be integrated inline and simulation results that are correlated with process parameter studies for different materials.

Highlights

The use of aspheres have been attracting a large amount of attention as they enable lens system designers to decrease the number of lenses, and the number of optical surfaces, used
[1] The variety of process parameters affect the final output of the process, but their individual and mutual effect is not clear
[3] Efficient polishing processes of fused silica surfaces down to few nanometres have been shown by various research teams. [4,5,6] Hildebrand et al.[4] performed a numerical simulation describing the influence of several process parameters

Summary

Introduction

The use of aspheres have been attracting a large amount of attention as they enable lens system designers to decrease the number of lenses, and the number of optical surfaces, used This lowered complexity can improve the performance of devices, reduce waste and lower the manufacturing cost. Achieving surface figure and roughness values for such freeform optics that are comparable with those of standard precision optical components still remains elusive and requires a full understanding of the complete production technology chain. This is not straightforward, when considering the complexity of the current optical component fabrication process. The above described conventional methods for polishing optics can rightly be considered as «more an art than a science». [1] The variety of process parameters affect the final output of the process, but their individual and mutual effect is not clear. [2] It is of interest to have a stable and fully understood process independent of material or product shape

Laser polishing of glass

Approach

In-line measurement strategy

Conclusion