Additive solid immersion lenses for enhanced collection efficiency of shallow NV centers by pulsed laser deposition and structurization of high-k amorphous oxides
The negatively charged nitrogen-vacancy ($\mathrm{NV}^-$) defect in diamond can be used for quantum information processing via the readout of the radiative decay of the excited state into the ground state. The large refractive index mismatch of diamond and air causes low photon extraction efficiency due to total internal reflection losses. Here, we investigate the photon extraction numerically and report additive solid immersion lenses (SILs) consisting of the high-k dielectric yttria-stabilized-zirconia (YSZ) for surface modification and enhanced light extraction of shallow implanted nitrogen-vacancy centers. We demonstrate an average increase of 63% in saturation intensity using a scalable bottum up room temperature pulsed laser deposition and photolithography structurization process. The average necessary laser intensity for saturation is reduced by 33% by the SILs.