Fraunhofer Institute for Applied Optics and Precision Engineering IOF
Fraunhofer Institute for Applied Optics and Precision Engineering IOF

LSM-Image of a Diffuser's Surface Relief Structure

Tailored Light Diffusers

Star-shape diffuser element.
Star-shape diffuser element.

Tailored Light Diffusers enable the efficient transformation of incoming light into a desired angular distribution at the far field. The design and simulation processes base upon rigorous wave-optical methods. The concurrence of refractive and diffractive behavior of superficial microstructures results in achromatic characteristics and effective suppression of zeroth order and ghost-images. The realization of customized surface patterns with the help of direct-writing grayscale lithography as a mastering technology offers almost arbitrary far field distributions and light deflection for illumination and display purposes.

- rigorous and wave-optical design methods

- Mastering by direct-writing grayscale lithography

- Substrate size up to Ø 300 mm

- Photoresist master for replication (e.g. UV molding)

- Mask for RIE proportional transfer into fused silica, borofloat glass, silicon

 

Diffuser's surface relief structure (SEM image).
Diffuser's surface relief structure (SEM image).

Characteristics

  • Full angle up to 120°
  • High efficiency from UV to IR spectral range
  • Achromatic characteristics
  • Suppression of zeroth diffraction order and ghost images
  • No induced absorption
  • Local variable angular distribution and tilt function
Characterization of a rectangular shape diffuser in a lab setup.
Characterization of a rectangular shape diffuser in a lab setup.

Addressed applications

  • Customized angular distributions for illumination tasks
  • (Laser-)beam shaping elements
  • Compact and highly efficient LED homogenization
  • Projection screens (translucent or reflective) e.g. for intermediate image plane

Further Information

In the »IBELIVE« project (german link: IBELIVE) innovative hybrid diffusers for low-profile lighting systems with tailor-made light distribution are being developed in cooperation with Continental Automotive GmbH.