Fabrication of high integrated microlens arrays on a glass substrate for 3D micro-optical systems

Microlens array have been developed as an essential element in integrated micro-optical systems. However, rapidly fabrication of high integration, high fill factor and multi-layer microlens arrays on a hard material is still a challenge. Here, facilely designed high integrated double-sided concave microlens arrays were proposed. These concave microlens arrays possess nearly 5000 close-packed microlenses on a double sides glass substrate, which were created by femtosecond laser wet etch process. The optical properties of integrated microlens arrays were investigated, which exhibit novel diverse imaging patterns, such as coaxial nested rectangular-shaped, coaxial nested hexagonal-shaped, non-coaxial nested hexagonal-shaped imaging patterns, etc. Moreover, diverse imaging patterns can be simply realized by controlling the shape, the size of the microlenses and the arrangement of the microlens arrays on the double-sided glass chips.