Substrate Integrated Microlenses Prepared by the PCVD-Technique for Laser-Fiber Coupling

Microlenses for laser-fiber coupling purposes were prepared using an etching process in combination with a plasma-activated chemical vapor deposition (PCVD) process. The lenses take the form of half spheres or spheres with a diameter of~ 60 μm. They were characterised using a light source whose NA = 0.4. The coupling efficiency of the lenses, obtained when coupling the light into a graded-index fiber with a core of 50 μm diameter whose NA = 0.21, was 84%.