Open AccessFabrication of aspherical SU-8 microlens array utilizing novel stamping process and electro-static pulling method
Author(s) -
Shih-Ming Kuo,
Che-Hsin Lin
Publication year - 2010
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.18.019114
Subject(s) - microlens , fabrication , materials science , optics , focal length , stamping , substrate (aquarium) , surface roughness , curvature , optoelectronics , lithography , lens (geology) , physics , composite material , medicine , oceanography , alternative medicine , geometry , mathematics , pathology , metallurgy , geology
A simple and novel method is proposed for the fabrication of aspherical SU-8 microlens arrays with a wide range of tunable focal lengths utilizing a soft SU-8 stamping process and an electro-static pulling method. In the proposed approach, an SU-8 stamp incorporating a micro-nozzle array and a reservoir containing unexposed SU-8 is fabricated on a glass substrate using a dose-controlled exposure process. Microlens arrays with diameters ranging from 20 to 500 μm and various radii of curvature are successfully fabricated using the proposed method. The low surface roughness (Ra = 3.84 nm) and high dimensional uniformity of the SU-8 microlens arrays (variation < 5% designed diameter) confirm both the optical quality of the individual microlenses and the general feasibility of the fabrication method. The innovative fabrication method proposed in this study provides a simple and efficient means of producing high quality aspherical microlens arrays with tunable focal lengths.