We offer our customers a wide spectrum of capabilities and services in the field of microstructured plastic optics. It comprises the complete cycle from optical design and development to manufacturing, product enhancement and final inspection of the finished good.
This integration of capabilities has given us a high degree of flexibility. It ensures our customers of having just one partner from the idea for a product to its final realization.
Fresnel Optics GmbH
Flurstedter Marktweg 13
99510 Apolda, Germany
Tel.: +49 3644 50110
We have many years of experience in the optical design of microstructured surfaces. No matter whether we receive a lens design from a customer or whether a new design is required, we support our customers when it comes to realizing their ideas. For the calculation and simulation we use specialized software. We take into account the specific material properties as well as the feasibility of the design when it comes to tool and part production.
The fabrication of tools is the most important prerequisite for the manufacture of high-quality and precise microstructured plastic optics. Decades of experience in microreplication enable us to realize tools in different designs and with tight tolerances.
Starting point for our production tools are the original master tools. They are manufactured by ultra-precision machining (UP). Different technologies, such as UP-diamond turning, UP-flycutting and UP-linear ruling, are available at our tooling center in Apolda and the USA.
Tooling Tree Concept
The master tool is the basis for the so-called tooling tree. In an electroforming process several copies of the master tool are created.
For the fabrication of the optical components themselves only the stampers are used. Normally the customer only pays once for the tooling and we guarantee the long-term delivery capability of a product in a constantly high level of quality.
In addition we offer the fabrication of prototypes. In this case, a fresnel lens is cut directly into a plastic substrate by diamond turning. This enables customers to evaluate a lens design within a short time frame.
Softtool - Process
During the last years we have successfully further developed our softtool-process. We are now able to assemble tools precisely according to different customer requirements
Precision Polymer Replication
Depending on the product and the customer requirement we can choose between different manufacturing processes. We have the possibility to fabricate our components in a compression molding and a special injection-compression molding process. Apart from this, we offer a casting process for the fabrication of hybrid-optics (Silicone-on-Glass). All those processes offer a high contour accuracy and surface quality as well as small tip rounding.
Silicone on Glass
In our casting process we manufacture microstructured optics on silicone-on-glass (SOG) basis. A very thin silicone layer is applied onto a glass substrate. The microstructured is then molded into this layer.
The result is a component which is ideally suited for outdoor applications. We can fabricate SOG-optics in different thicknesses and sizes.
For more sophisticated or complex applications we offer a wide range of product enhancements and are able to specifically modify or improve the characteristics of polymer surfaces. Among others, we can apply different coatings or anti-reflective nanostructures as well as printings.
We offer different anti-reflective and reflective coatings which always consider the specific characteristics of the various polymer materials. There are a number of standard coatings available but we also develop custom coatings according to the customer’s requirements.
We apply anti-reflective coatings on polymer substrates - no matter whether they have a plano, a structured or a continuous surface. Upon request we can adapt the AR-coatings to an individual wavelength or to a wide range of wavelengths. It is also possible to combine interference layers with hard coatings.
Interference Layers and Standard Layers
It is possible to apply reflective coatings so that our plastic optics can be used as mirrors. Our most common coating is aluminum, but we can also use different materials such as gold. We deposit the metal layer and optionally a protective layer on the structured side of the optic.
Anti-reflective nanostructures represent an interesting alternative to conventional interference layers. They reduce unwanted light reflections and show a broad band anti-reflective effect. We offer different types of nanostructures, the stochastic structure PlasmAR® and the periodic Motheye structure.
The Motheye-structure is a periodical nanostructure and can be described as an optical grating. It can be applied on plano surfaces by compression molding.
Our PlasmAR®-nanostructure functions as a graded index layer and is stochastically arranged with different heights and widths of the structure. This irregular arrangement avoids angle depended reflections. The structure can be applied on plano as well as on structured or continuous surfaces.
Depending on the application it can be necessary to protect sensitive surfaces. We offer scratch resistant hard coatings for plano surfaces. In our process we use an UV-curing lacquer which is evenly applied on substrates up to 19” in diameter. Our hard coatings are resistant according to DIN 52347.
We offer different printing options for our polymer optics. For smaller areas (for logos) we use a pad printing process, whereas for larger areas we use our silk screen printing process.
Each component leaving our plant is trimmed by CNC milling. We are able to cut the parts to virtually any shape in close tolerances. Based on state-of-the-art equipment, we can work flexibility without sacrificing the components' precision and quality.
Certified according to ISO 9001 since 1996, our internal processes are cleary structured and organized. Guidelines for quality control and respective assessment procedures cover our entire activities.
For quality control we use standard metrology and also customized measuring systems for functional tests. In addition, each optical component is checked in our final inspection prior to shipping.