Fraunhofer Institute for Production Technology IPT
Fraunhofer Institute for Production Technology IPT
© Fraunhofer IPT

Infrared optics made of chalcogenide glass

Know-how in chalcogenide glass molding paves the way for economically efficient mass production of affordable infrared optics for growth markets and for the emergence of new applications.

© Fraunhofer IPT

© Fraunhofer IPT

Mass production of freeform optics

Glass optics with complex, non-rotationally symmetrical geometries can be manufactured efficiently in precision glass molding operations.

© Fraunhofer IPT

Optics from Aachen – Leading manufacturing

We have every production stage on the supply chain covered – from designing optical systems all the way through to the final component qualification.

Precision glass molding

High precision glass optics with complex forms are key components for innovative products in mass and growth markets such as laser technology, medical technology, digital imaging, the automotive sector and for sensor systems. Glass optics of this nature can be manufactured economically in isothermal precision glass molding processes.  These involve heating and molding glass blanks in the form of spheres, polished discs or wafers between two ultra-precise mold halves then cooling them under controlled conditions. The net shape optics can subsequently be released from the molds. We apply anti-wear coatings specially developed in-house to ensure economical tool life despite high forming temperatures and forces.  

Precision glass molding opens up an enormous variety of possible geometries and glass types

In contrast to conventional grinding and polishing manufacturing processes, precision glass molding, which is a replicative production process is ideally suited to the manufacture of optical components with particularly complex geometries such as aspheres, diffractive structures, lens-arrays or freeform-optics.

Scaling tool systems is the key to efficiency

The outstanding feature of precision glass molding is the scalability of production achieved by using multi-cavity molds or by adopting a wafer-based manufacturing approach. A large number of defined glass blanks are molded into net-shape lenses in one modular, multi-cavity tool.

By virtue of its use of monolithic half molds and glass in the form of wafers polished on both sides, wafer-based production achieves a vast increase in packing density and a large number of molded lenses in each molding process. In order to reduce the manufacturing cost of infrared optics even further, we are currently working with our partners within the ongoing SKALIR research project to drive forward the development of both approaches.

Our Services

  • Feasibility studies
  • Process development and prototype production
  • Technology transfer
  • Support in the ramp-up to mass production
  • Development of the entire process chain for replicative glass optics production
  • Scaling glass shaping processes
  • Analysis and optimization of glass molding processes at your premises

Low-Tg glass

For challenging optical applications, we use a range of optical, low Tg glass, molded at temperatures below 630 °C using tools made of binderless cemented carbide. Companies operating in the optical industry can use a wide range of moldable, low-Tg glass covering a refractive index of nd = 1.4 – 2.1 and a range of Abbe numbers from 18 to 95 to exploit the enormous potential for innovative optic designs on the visible spectrum.

Chalcogenide glass

High performance infrared optics for mass markets can be manufactured with a high degree of material efficiency from chalcogenide glass. The low molding temperatures below 400 °C make it possible to use economical mold materials such as aluminum alloys which can be machined using single point diamond turning.

The Fraunhofer IPT integrates mold design and manufacturing within existing process chains for companies in the infrared sector. As part of the BMBF-funded "MIRO" research project, we have newly developed anti-wear coatings designed specifically for molding of chalcogenide glass.

Fused Silica

Fused Silica (quartz glass) is characterized by its excellent level of transmission with minimal internal absorption. Consequently, it has enormous potential for high-power optics. However, it can be shaped only at temperatures exceeding 1000 °C. This presents manufacturing companies with the challenge of developing tools capable of withstanding such extreme temperatures.

The Fraunhofer IPT is therefore developing new tool materials and coatings in order to facilitate the manufacture of high-power fused silica optics.

Quartz glass forming

Typical products produced in precision glass molding operations

© Fraunhofer IPT

Aspherical lenses

High-precision aspheres with form accuracy below 300 nanometers for imaging optical systems and laser technology

© Fraunhofer IPT

Microlens arrays

Arrays consisting of aspherical or acylindrical microlenses for use as monolithic components or as individual lenses.

© Fraunhofer IPT

Structured optics made of glass

Diffractive and nano-structured optical surfaces permit beam-shaping in laser systems, the correction of color errors or integration of an anti-reflex function.

© Fraunhofer IPT

Infrared lenses

Economical and material-efficient production of infrared lenses from chalcogenide glass

© Fraunhofer IPT

Freeform optics

Efficient manufacture of non-rotationally symmetrical, freeform glass optics

© Fraunhofer IPT

Glass tools

High-precision tools made of glass for mass production of plastic optics such as contact lenses via UV and thermal curing