Single-pulse writing of a concave microlens array.

ABSTRACT

This work developed a method of femtosecond laser (fs-laser) parallel processing assisted by wet etching to fabricate 3D micro-optical components. A 2D fs-laser spot array with designed spatial distribution was generated by a spatial light modulator. A single-pulse exposure of the entire array was used for parallel processing. By subsequent wet etching, a close-packed hexagonal arrangement, 3D concave microlens array on a curved surface with a radius of approximately 120 µm was fabricated, each unit lens of which has designable spatial distribution. Characterization of imaging was carried out by a microscope and showed a unique imaging property in multi-planes. This method provides a parallel and efficient technique to fabricate 3D micro-optical devices for applications in optofluidics, optical communication, and integrated optics.