Precision in series manufacturing is a question of design. 05. September 2022 The close interaction between optics design and manufacturing gives customers a certainty of planning and costs. Dr. Stefan Zotter, Photonic site manager in the Austrian Wild Group, specifies: “It guarantees that we develop with series production in mind right from the start.” Increasingly complex geometries, miniaturization as well as growing demands for precision, quality, and cleanliness are most important on the product side. New materials, innovative processes, and measurement technologies are the important parameters on the manufacturing side: To produce high-performance optical products, such as those for medical technology, the workflow from optical design to precise manufacturing and quality control must be perfectly coordinated. In addition, a close look at economic factors is necessary. LP.PRO: Dr. Zotter, how well does this coordination work at Wild? Dr. Zotter: If development and production run in separate worlds, the temptation is often great that designers optimize where production reaches its limits later. At the Wild Group, this is different. We know how crucial the interaction between design and manufacturing is to produce high quality optics time- and cost-efficiently in small and large quantities. Our production and the accompanied understanding of manufacturing tolerances and potential cost drivers bring several advantages. So does the fact that the group brings together a variety of competencies, from feasibility studies to modern simulation methods and prototyping, right through feasibility studies to modern simulation methods and prototypes in small and large quantities. LP.PRO: You develop and manufacture optical and optomechatronic products exclusively on behalf of customers. What is special about your service? Dr. Zotter: Basically, optical design has the task of efficiently achieving an application-specific imaging quality and light distribution. It is therefore not limited to the design of an optic, but also includes detailed sensitivity and tolerance analyses. We examine all potential tolerances, such as deviations from the nominal radius of the lens, refractive index fluctuations of the glass or the fit clearance between the lens and the lens mount. All of these can affect the performance parameters of the optical system. Only when all undesirable influences are analysed and reduced already in the design phase, a system can be created that delivers the required optical performance – starting with the first prototype. LP.PRO: This means that at the beginning of a project, many things are open, the path is not fixed? Dr. Zotter: Flexibility in design and openness in thinking are very important. They are possible thanks to the wide range of manufacturing options that are available to us. A system is not trimmed to a specific, possibly inefficient manufacturing process. We rather optimize it for the manufacturing method that best solves the problem and generates the highest value for the customer. In addition, design for manufacturing reduces the time to market significantly. As the feasibility is already taken into account during the simulation the number of correction loops on the prototypes is reduced. LP.PRO: Which development tools do you use? Dr. Zotter: Our optical designers use the simulation software Zemax OpticStudio for imaging optics and LightTools for illumination optics. Where the standard functionalities of these tools are not sufficient, they write their own scripts with Python, among other languages. However, it is important, to constantly verify the results with experiments on the optical table or in prototyping and to integrate the measurement results from production into the tolerance models of the designs. These valuable feedback loops between production and optical design set us apart from conventional design offices and pure optics manufacturers. LP.PRO: Photonic, as a technology partner within the Wild Group has established a lot of know-how in lighting optics. What is your specialty? Dr. Zotter: Our experts at Photonic deal mainly with non-imaging optical systems and free-form optics. The know-how in illumination optics benefits almost all optical applications. For example, in fluorescence-assisted tumor resection, in addition to modern display and camera technology, lighting plays a key role in implementing augmented reality solutions for medical technology. Only those who have the necessary expertise in operating room procedures, physiological backgrounds and technical know-how can develop a device that provides added value for the user in the operating room. The same applies to in-vitro diagnostics: Among other things, suitable lighting technology is required here for the multispectral evaluation of molecular biological samples. LP.PRO: What role does the latest technical equipment play for you? Dr. Zotter: Photonic has recently invested in the optics and electronics lab by installing new assembly stations for prototypes and demonstrators. These are equipped with cameras and IT, so that the assembly stations can be prepared for series production on site and training can be carried out virtually. Optical high-end measurement equipment is also very important. Its quality comes close to that of test laboratories at the Wild Group. Thus, the optical designers have direct comparability of their measurements with those of the certification offices, which minimizes waiting times, accelerates development and results in a shorter lead time to production. LP.PRO: What kind of equipment is involved? Dr. Zotter: Among the technical highlights of the new optics laboratory is a CAS-140D spectrometer with integrating sphere (Ulbrichtkugel) from Instrument Systems – for high-precision spectral light measurement. It has high sensitivity and high measurement dynamics, which benefits us in the acquisition of fluorescence signals. As a result, the knowledge gained from the functional samples has increased which makes development even more efficient. We have also added an LMK colour and luminance measurement camera, which is used to measure spectral components and the energy distribution of illumination fields. Also new is a power meter for the measurement of lasers in the NIR, and even faster photodiodes for measuring laser fluctuations in lasers. In addition, we have created a database of light sources, which has been linked to a software for spectral combination. This knowledge shortens the concept phase, as the light source research is much faster now. LP.PRO: You also support and advise your customers beyond development and production. Dr. Zotter: That is correct. Many companies know the problem, on the one hand they rely on consulting companies who support them in regulatory matters. On the other hand, they get technical know-how from contract manufacturers and developers. Very few offer a combination of both. This is where the Wild Group stands out, as due to the development and production of medical technology products it had to react on these requirements early on. In-house system architects and quality engineers are at our customers’ disposal to cope with their increased documentation. Because regulatory affairs start with the product idea. Those who gain experience and knowledge in this area right from the start can put themselves in a more favourable starting position. LP.PRO: Thank you for the interview.