title: Waveguide-coupled micro-ball lens array suitable for mass fabrication.
abstract: We demonstrate a fabrication procedure for the direct integration of micro-ball lenses on planar integrated optical channel waveguide chips with the aim to reduce the divergence of light that arises from the waveguide in both horizontal and vertical directions. Fabrication of the lenses is based on photoresist reflow which is a procedure that allows for the use of photolithography for careful alignment of the lenses with respect to the waveguides and enables mass production. We present in detail the design and fabrication procedures. Optical characterization of the fabricated micro-ball lenses demonstrates a good performance in terms of beam-size reduction and beam shape. The beam half divergence angle of 1544 nm light is reduced from 12.4 ° to 1.85 °.
authors.forename: Lantian
authors.initials: L
authors.lastname: Chang
authors.forename: Meindert
authors.initials: M
authors.lastname: Dijkstra
authors.forename: Nur
authors.initials: N
authors.lastname: Ismail
authors.forename: Markus
authors.initials: M
authors.lastname: Pollnau
authors.forename: René M
authors.initials: RM
authors.lastname: de Ridder
authors.forename: Kerstin
authors.initials: K
authors.lastname: Wörhoff
authors.forename: Vinod
authors.initials: V
authors.lastname: Subramaniam
authors.forename: Johannes S
authors.initials: JS
authors.lastname: Kanger