Efficient LED beam shaping with maskless irregular fly’s eye condenser, its realistic modelling and stray-light analysis

Maskless irregular fly’s eye condenser (iFEC) is a highly effective element for a beam shaping of arbitrary intensity profiles in the far field. The absence of absorbing masks ensures high transmittance for the pre-collimated LED source, and enables cost-effective monolithic mass production, such as high-precision injection molding. However, completely maskless beam shaping introduces new challenges, especially in terms of stray-light suppression and analysis. The iFEC structure required to obtain the target intensity profile must be achieved without appearance of sag height jumps in the interlenslet areas due to the risk of pronounced stray-light features. Additionally, since in a maskless design the entrance lenslets themselves act as objects for constructing the far-field image of the beam, manufacturing limitations must be closely considered at the design stage and reflected in the micro-optics modelling. In this work we propose an exemplary system with iFEC as well as an established design and modelling approach for realistic beam simulation and stray-light identification.