Regular paper

Optical path difference evaluation of laser-soldered optical components

¹ Fraunhofer Institute for Applied Optics and Precision Engineering IOF, Albert-Einstein-Str. 7, 07745 Jena, Germany
² Numerik Jena GmbH, Im Semmicht 4, 07751 Jena, Germany

^* thomas.burkhardt@iof.fraunhofer.de

Received: 11 September 2015
Revised: 2 December 2015

Abstract

We present Solderjet Bumping, a laser-based soldering process, as an all inorganic joining technique for optical materials and mechanical support structures. The adhesive-free bonding process enables the low-stress assembly of fragile and sensitive components for advanced optical systems. Our process addresses high demanding applications, e.g. under high energetic radiation (short wavelengths of 280 nm and below and/or high intensities), for vacuum operation, and for harsh environmental conditions. Laser-based soldering allows the low stress assembly of aligned sub-cells as key components for high quality optical systems. The evaluation of the optical path difference in fused silica and the radiation resistant LAK9G15 glass components after soldering and environmental testing shows the potential of the technique.