Berliner Glas Group employees working in design, engineering or technology service functions regularly participate in conferences as speakers and publish white papers and technical articles.
We have linked the specialist articles that have appeared in various magazines or databases.
The white papers can be downloaded right here after a short registration:
Technical Article Microalignment in the optical Industry
German article - see description on the German page
Technical Article Description of aspheric surfaces
Aspheres and cylindrical lenses are key optical components developed and manufactured by the Berliner Glas Group. Berliner Glas has published an overview article in which the various forms of description of such surfaces are considered. The surface descriptions listed in the current version of "ISO 10110, Optics and photonics - Preparation of drawings for optical elements and systems - Part 12: Aspheric surfaces" are listed herein, as well as other forms derived from older work.
The various forms of the arrow height formulas are compared and thereby the peculiarities and their advantages and disadvantages are shown. In the article, the calculations of the orthogonal polynomials used for this as well as the partial derivatives of the heights of the arrows are explicit for all considered forms, as they are hardly found anywhere else in this completeness. In addition to the rotationally invariant aspheres, more complex surface forms up to the noncircular cylinder surfaces are also considered.
This article was published in Advanced Optical Technologies. Vol. 8, Issue 3, 2019 and can be read and downloaded directly online.
Technical Article Ultra-precision grinding
The SwissOptic AG in Heerbrugg, a company within the Berliner Glas Group, is specialized in the development and production of customized aspheres and freeform surfaces. The technical article "Ultra-precision grinding: When glass behaves like ice-cream" gives some insights on their expertise.
When manufacturing aspheres, extensive polishing processes are often needed to achieve highest precision. A new ultra-precision grinding process, however, promises to reduce the amount of time spent on polishing considerably.
This article was published in laser+photonics 01/2017 and can be downloaded there:
White Paper Wafer Backside Particle Reduction
Chucks are used in various areas of the semiconductor industry: in lithographic processes, inspection steps, coating, 3D integration, wafer handling, during etching processes etc.. During all these processes backside contamination (BSC) of wafers is a big problem. One source for backside contamination is the wafer chuck.
Berliner Glas designs and produces customized electrostatic and vacuum chucks with a specific pin or mesa design to make the chuck as resistant as possible to particle contamination. To reduce the contact area between the wafer and the chuck even more the specialists in the Berliner Glas development team continue their research constantly. The here presented White Paper shows results of measurements which were performed to investigate the behavior of the different pin properties in terms of added particle.
Technical Article Measuring Large Non-planar Optics
The evaluation of the surface form quality of large-scale optical components in general and large cylindrical components in particular is most challenging. Such surfaces can be measured with planar Fizeau-type interferometers equipped with computer generated holograms.
Berliner Glas wrote a technical article that provides an overview of the measurement process using sub-aperture stitching techniques, the degrees of freedom of the measuring system, the requirements on input data and the importance of error-corrected holograms.
This article was published in the December edition of the magazine Optik & Photonik (05/2015) and can be downloaded directly from the Wiley Online Library.
Technical Article Corrosion of Borosilicate Glasses
When glass comes in contact with water, the result is often the corrosion of the glass – the surface structure of the glass is changed. During the production processes – polishing, cleaning and etching – contact between the alkaline free borosilicate glass and water is inevitable. It is therefore essential to know what changes take place, in order to realize critical processing steps.
The Berliner Glas Group has researched and applied a variety of processes and so determined the effect of the different phases of production on the borosilicate glass.
The "IMAPS/ACerS International Conference and Exhibition on Ceramic Interconnect & Ceramic Microsystems Technologies CICMT 2015" took place at the "Fraunhofer IKTS" in Dresden, Germany, from April 20-23, 2015. During this conference the Berliner Glas Group presented the results of the above mentioned research. The most critical of these results were published in a technical article.
Technical Article High-Performance Mirror for Space Applications
The Berliner Glas Group attended the ‘International Conference on Space Optics’ (ICSO), 7-10 October 2014, with a presentation about space mirrors. The paper and presentation as well as all sessions of the conference can be reviewed in the ICSO Proceedings online resource.
This technical paper includes the technical requirements that have to be met by these mirrors, the solution of the Berliner Glas Group as well as the advantages that the design and the features of the mirrors provide. These plane elliptical shaped mirrors are part of the Synopta Coarse Pointing Assembly (CPA) being one of the key elements of the TESAT Spacecom Laser Communication Terminals (LCTs) that are used for laser communication in space.
White Paper Perfecting Chucks
Chucks are used in various areas of the semiconductor industry: in lithographic processes, inspection steps, coating, 3D integration, wafer handling and during etching processes. Two key factors of chucks are clamping force and flatness. Therefore Berliner Glas has developed methods to model, test and optimize the effective clamping force and the resulting flatness.