Research Of Fabricating Micro-Lens Array Using Real-Time Dynamic Digital Lithography

With the development of micro optical and the improvement of micro-machiningtechnology, the dimension of micro optical elements is more and more small, and theycan realize the functions of microminiature, array and integration. Almost in allengineering application fields such as information processing, military, biomedicineand entertainment, micro-lens array are showing important application value and wideforeground because they can process light information with high speed. The design andfabrication of micro-lens array has become one of the most popular researches inrecent years.Photography technology experienced the development from mask era to non-maskera because of the improvement of design theory and fabrication method. Digitalphotography have many advantages such as save materials to reduce the cost, easy tofabricate, high precision, have no overlay deviation. Because it has so manyadvantages, people pay more and more attention on it. In this paper, the design andfabrication of micro-lens array based on digital photography was primarily studied.The research contents and results are listed below:First of all, the feature of DMD (Digital Micromirror Device) was fully analyzed. Anew method of fabricating micro-lens array was proposed based on DMD digitalphotography technology.Secondly, Introduced and analyzed the digital moving mask skill and the digitalrotating mask skill. According to the scalar diffraction theory and the relation betweenphase function and relief profile function, the digital mask of microlens is designed.The distance between the single micro-lens can be controlled by computer easily.According to this method the design of digital mask of micro-lens array is flexibly, atlast draw the digital mask by the means of programming with CorelDRAW.Finally, a real-time dynamic digital lithography method is proposed. The computeroperator controls the digital mask to movement that is uniform to vertical or rotary inthe DMD. By controlling the speed and exposure time to control the exposure, it canobtain a complete micro-lens array in optical substrate one time. In this paper, manycontrast experiments are carried out to confirm the feasibility and superiority of this method.