Simple fabrication of high focal number micro-lenses based on a microfluid pulse jetting method

Abstract

In this paper, we demonstrate a simple and rapid high focal number (F # ) micro-lens (ML) fabrication method using a simple microfluid pulse jetting technology. The simulation of the microfluid pulse jetting is firstly studied to prove that the new jetting method have the potential for jetting the UV polymer with a low surface tension coefficient stably. As the high F # of the ML is ascribed to the low contact angle of the ML on the substrate, a simple surface treatment of the substrate is adopted to obtain a small contact angle of the UV polymer on the substrate. Based on this method, the spherical ML and cylindrical ML with a F # as high as 11.5 have been successfully fabricated. The fabricated high F # ML is characterized through simulating the modulation transfer function curve, wavefront aberration, and point spread function (PSF) and measuring the PSF and imaging effect, and the simulation and measurement results indicate that the diffraction limit optical performance of the high F # ML can be achieved and the clear images can be observed.