CO 2 laser thermal reflow shaped convex glass microlens array after Bessel picosecond laser inscribing and hydrofluoric acid processing

In this paper, a convex micro-glass lens array fabrication process that utilizes ${{\rm CO}_2}$CO2 laser thermal reflow in the Bessel picosecond laser inscribing and hydrofluoric acid processed micro-glass pillars array is presented. The Bessel picosecond laser permits high tolerance and precise micro-pillar fabrication. In the thermal reshape process, the ${{\rm CO}_2}$CO2 laser power, relative defocus length, and scanning velocity are three crucial parameters to the microlens array’s focal length. By using this method, microlens arrays with focal length ranging from several tens of micrometers to several hundred micrometers can be created. This research provides another way to fabricate convex micro-glass lens arrays with several hundred micrometers focal length in good utility.