Any kind of light distribution can be generated with a single optical free-form element. The beam is shaped by reflective or refractive intensity redistribution.
On this basis, these beam shapers are used for both incoherent sources (LEDs, halogen lamps) and lasers.
The profile of the optical element is defined by a large number of simple, problem-specific fundamental elements:
The profile of the beam shaper consists of a basic structure – for beam deflection and focusing on the target as well as a microstructure – for redistribution of the light intensity in the desired target distribution.
Special design algorithms ensure continuous element profiles without gradations and shadowing phenomena. The design for finitely extended light sources is possible with specially-adapted iteration algorithms which generate maximum efficiency in the beam transformation.
Single-point diamond turning with a fast-tool servo (FTS) enable the simultaneous production of the basic structure and microstructure. On-axis or off-axis spherical and aspherical surfaces form the base surface.
The lateral and axial resolution of the microstructure is determined by the properties of the FTS, which are taken into account in the design. Perfect synchronization of all movements and a suitable selection of the processing regime ensure sufficient precision and quality of the free-form elements, which can subsequently be molded (injection molding, molding in polymer or glass).
Data transfer from the design to the production process is achieved through direct programming of the DSP control of the FTS.
Fraunhofer Institute for Applied Optics and Precision Engineering IOF