- Efficient collection of fluorescence light is essential for all optically adressable qubit platforms. For the nitrogen-vacancy (NV) center in diamond, the high refractive index of the host medium poses a major challenge as it limits the solid angle under which fluorescence light can leave the crystal. To enhance collection efficiency from single NV centers, we design and simulate micro-optical elements that shall be directly fabricated on the diamond surface using two-photon polymerization. Several optical designs and photoresists are evaluated for their expected coupling efficiency into single-mode fibers and their tolerance to fabrication errors. Additionally, an analytical solution for single lens collimation of the emission of a point source in diamond at a specific wavelength is presented, as well as considerations regarding the degradation of wavefront quality in multi-wavelength Fresnel designs.