Description

Micro-optics are critical components in areas as relevant as energy harvesting, sensing, and telecom, but current fabrication strategies can be limited in throughput, fill-factor, range of suitable substrates, or flexibility in the choice of lens design. These issues represent a heavy burden toward the expansion of micro-optical elements in emerging applications such as flexible optoelectronics or lab-on-chip systems. Here we introduce laser catapulting or LCP, a novel and simple direct-write method for the rapid preparation of tailored microlenses and high fill-factor micro-lens arrays (MLAs) onto arbitrary substrates. LCP uses single laser pulses to delaminate and transfer microdisks from a polymeric thin film into user-selectable positions of a targeted surface. After a thermal reflow process, the disks are converted into microlenses. By shaping the laser beam, LCP enables the transfer of polymeric microdisks with various geometries resulting in spherical, cylindrical or triangular microlenses. Additionally, the softening of the polymer during thermal reflow and the action of surface tension produces microlenses with an almost perfect surface quality (<5nm roughness). We provide a theoretical background of the mechanisms responsible for laser catapulting and demonstrate the validity of our approach in micro-optics by preparing and characterizing 100% fill-factor arrays of microlenses with different radii of curvature, geometries, and arrangements over various surfaces, including rigid, soft, curved and even flexible. As a proof of concept, we use LCP to fabricate, in-situ, different MLAs directly on top of SPAD arrays, and quantify the achieved enhancement in light collection efficiency.

Contributing Authors

  • Salvatore Surdo
    Istituto Italiano di Tecnologia
  • Alberto Diaspro
    Istituto Italiano di Tecnologia | University of Genova
  • Martí Duocastella
    Istituto Italiano di Tecnologia | University of Barcelona
Salvatore Surdo
Istituto Italiano di Tecnologia
Track: Laser Additive Manufacturing
Session: On-demand Only
Date/Time:
Location:

Keywords

  • 3D Printing
  • Laser Additive Manufacturing
  • Microlenses