Abstract
Out-of-plane microlenses and microoptical fiber holder are two of the most important components for building an integrated microoptic system with a precise alignment accuracy. In this paper, a simple and convenient method to fabricate these components from SU-8 by using inclined UV lithography in water is proposed. It consists of two perpendicular exposures in SU-8 at ±45°. DI water possesses a low absorption coefficient and a moderate and stable value of refractive index in near UV. Using water, the exposure angle in SU-8 can be increased to 50° from 35° in air necessary to pattern the desired 45° slope of the sidewalls. The principle of the proposed technique and the detailed fabrication process of the microoptic components will be presented. The integratability of the fabricated components was demonstrated by the fabrication of the microoptical fiber holder with a pre-aligned out-of-plane microlens.
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Acknowledgments
The authors acknowledge the financial support from Defense Advanced Research Project Agency (DARPA) under Contract N66001-00-1-8943 and the State of Louisiana. The authors would like to express thanks to Dr. Varshni Singh of CAMD for evaluating surface roughness of microlenses and Liming Sun of LSU for her contribution in SU-8 resist processing and 3D microstructure fabrication.
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Ling, Z., Lian, K. SU-8 3D microoptic components fabricated by inclined UV lithography in water. Microsyst Technol 13, 245–251 (2007). https://doi.org/10.1007/s00542-006-0175-2
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DOI: https://doi.org/10.1007/s00542-006-0175-2