Free-Form Optics

Our range of services

Free-form optics are those with refractive and reflective surfaces that differ significantly from typical spherical and aspheric geometries. For customers from research and industry, Fraunhofer ILT develops tailor-made free-form optics for applications in various industries. These optics are used, for example, in the field of general, street and architectural lighting. They increase energy efficiencies and reduce operating costs.

Adapted optical free-form surfaces allow the redistribution of power through refraction and reflection. A goal here, for example, is to obtain the desired power density distribution at maximum light output with a minimum number of optical surfaces. Fraunhofer ILT develops algorithms for the design of optical free-form surfaces with which, for example, refractive and reflective surfaces can be combined in an optical element. The optical design creates virtual prototypes whose properties are checked with simulation software. Commercial and self-developed tools help to verify the lighting function and determine the influence of manufacturing and assembly tolerances.

The range of services offered by Fraunhofer ILT includes implementing ideas from the virtual prototype via the production-adapted design and measurement, characterization and functional testing of manufactured optics all the way to simulations and consulting.

High-efficiency freeform LED optics for street lighting.
© Fraunhofer ILT, Aachen, Germany.
High-efficiency freeform LED optics for street lighting.
Stretch of road lit using fewer lights.
© Fraunhofer ILT, Aachen, Germany.
Stretch of road lit using fewer lights.
Compact freeform lens for a fog light.
© Fraunhofer ILT, Aachen, Germany.
Compact freeform lens for a fog light.

Design of Highly Efficient Free-Form Optics for LED Applications

  • General and architectural lighting
  • Tailored illumination geometries
  • (Industrial / manufacturing) process illumination
  • Automotive lighting
  • Fiber coupling

Development of Prototypes

  • Virtual prototyping
  • Preparation of optics design data for manufacturing

Photometry for Illumination Applications

  • Measurement of luminance and illuminance
  • Single-shot measurement of luminous intensity distribution curves
  • Comparison of measurement and simulation


Our brochures offer a quick view onto our service portfolio. Find more detailed information in the “project results“ tab.


“Design of Freeform Optics“


“Optics Design and Diode Lasers“


Laser technology can solve demanding tasks in many different industries. Whether as a tool in automotive production, as measuring equipment in the environmental sector, as a diagnostic or therapeutic instrument in medical technology or as a communication medium in space technology, the laser provides multiple uses with high productivity and high efficiency.

Read up about the innovations of the Fraunhofer ILT in a few selected industries and convince yourself!


Research with us!

Please do not hesitate to contact us if you have any questions about general topics! Our contact persons are happy to get in touch with you.

Project Results


Hopmann, C., Brecher, C., Loosen, P., Röbig, M., Meiers, B., Berens, M.:
Mit Kunststoff in die optische Zukunft
Kunststoffe 2014 (10), 154-159 (2014)

Wester, R., Müller, G., Völl, A., Berens, M., Stollenwerk, J., Loosen, P.:
Designing optical free-form surfaces for extended sources
Opt. Expr. 22, (S2), A552-A560 (2014)

Bruneton, A., Bäuerle, A., Wester, R., Stollenwerk, J., Loosen, P.:
Limitations of the ray mapping approach in freeform optics design
Opt. Lett. 38 (11), 1945-1947 (2013)

Bruneton, A., Bäuerle, A., Wester, R., Stollenwerk, J., Loosen, P.:
High resolution irradiance tailoring using multiple freeform surfaces
Opt. Expr. 21, Nr. 9, 10563-10571 (2013)

Wester, R., Bäuerle, A.:
Light shaping for illumination
Adv. Opt. Technol. 2 (4),301-311 (2013)

Bäuerle, A., Bruneton, A., Westerm R., Stollenwerk, J., Loosen, P.:
Algorithm for irradiance tailoring using multiple freeform optical surfaces
Opt. Expr. 20, Nr. 13, 14477-14485 (2012)

Bruneton, A., Bäuerle, A., Traub, M., Wester, R., Loosen, P.:
Irradiance tailoring with two-sided, Fresnel-type freeform optics
In: Nonimaging Optics: Efficient Design for Illumination and Solar Concentration IX, San Diego, California, USA , August 12, 2012. Proc. SPIE  8485, 1-7 (2012)

Wester, R.,  Bruneton, A., Bäuerle, A.,  Stollenwerk, J.,  Loosen, P.:
Irradiance tailoring for extended sources using a point-source freeform design algorithm
Optical Systems Design 2012. Barcelona, Spain, November 26, 2012. Proc. SPIE  8550, 85502 

Bäuerle, A., Schnitzler, C., Wester, R., Kirsten, M., Schlüter, H., Tewes, M., Laschefski, H., Loosen, P.:
Optical system design for a reflector-based LED food lighting module. 
Proc. SPIE 8123, 812306 (7 S.), 2011

Bruneton, A., Bäuerle, A., Loosen, P., Wester, R.:
Freeform lens for an efficient wall washer. 
Proc. SPIE 8167, 816707 (9 S.), 2011

Bäuerle, A., Wester, R., Schnitzler, C., Loosen, P.
Design of efficient freeform lenses for mass-market illumination applications using hybrid algorithms
Proc. SPIE 7788, 778807 (10 S.)

Our services cover a wide range of topics. Related topics to free-form optics and further research and development focuses can be found under the following links.