Low-cost micro-lens arrays fabricated by photosensitive sol–gel and multi-beam laser interference

In this paper, we introduce a low-cost approach for fabricating micro-lens arrays that is based on photosensitive sol–gel and multi-beam laser interference. UV photosensitive ZrO2 gel films are prepared with Zr(O(CH2)3CH3)4 and BzAcH as the precursor and chemical modifier, respectively. With UV laser irradiation via different dose, nonlinear photodecomposition occurs in this film. Large scale 2D micro lens arrays with the sizes of 830 nm × 830 nm and 280 nm × 280 nm are fabricated by four-beam laser interference. The surface profile modeling shows that the micro lens is plano convex lens, and the effective focal lengths are 812.0 nm and 317.6 nm, respectively.

► An improved sol–gel method — photosensitive sol–gel is proposed, by which UV photosensitive Zr4+ contained sols and gel films are prepared.
► With UV laser irradiation via different dose, nonlinear photodecomposition occurs in Zr4+ contained films.
► Large scale 2D plano convex lens arrays with deep-submicron size are fabricated by four-beam laser interference using the photosensitive gel films and no chemical or dry etching transfer is needed.