  We report the design, nanofabrication, and characterization of high-quality
polymer-based micromirror structures employing the 3D two-photon polymerization
lithography technique. Compared to conventional microcavity approaches, our
innovative concept provides microstructures which allow fast prototyping.
Moreover, our polymer-based mirrors are cost effective, environmentally
sensitive, as well as compatible with a wide range of wavelengths from NIR to
the telecom C-band. We demonstrate polymer/air distributed Bragg reflectors and
full microcavity structures with up to 14 mirror pairs with a target wavelength
of 1550 nm and a reflectivity close to 99%. Additionally, our 3D printed
micromirrors are reproducible, mechanically stable, and enable hybrid
nanophotonic devices based on quantum dots, molecules or 2D quantum materials
as active medium.
