Characterization of the angular-dependent emission of nitrogen-vacancy centers in nanodiamond

Abstract

We report on the characterization of the angular-dependent emission of single-photon emitters based on single nitrogen-vacancy (NV-) centers in nanodiamond at room temperature. A theoretical model for the calculation of the angular emission patterns of such an NV-center at a dielectric interface will be presented. For the first time, the orientation of the NV-centers in nanodiamond was determined from back focal plane images of NV-centers and by comparison of the theoretical and experimental angular emission pattern. Furthermore, the orientation of the NV-centers was also obtained from measurements of the fluorescence intensity in dependence on the polarization angle of the linearly polarized excitation laser. The results of these measurements are in good agreement. Moreover, the collection efficiency in this setup was calculated to be higher than 80% using the model of the angular emission of the NV-centers.

Comparison of back focal plane imaging of nitrogen vacancy centers in nanodiamond and core-shell CdSe/CdS quantum dots

“…As can be seen, the NV-center emission is in good agreement with the model. The deviation of experiment and theory at about 40° may be caused by the blurriness in the back focal plane image [7]. The QD emission curve is accurately reproduced by the model the 2D dipoles despite a low signal-to-noise ratio.…”

“…Single-photon emitters based on a core-shell CdSe/CdS quantum dot and a nitrogen-vacancy center in nanodiamonds have been investigated with respect to their spectral and angular emission characteristics and their single-photon purity. Back focal plane imaging has been successfully conducted on the quantum dot and the results compared with those obtained from earlier measurements on a nitrogenvacancy center [7]. The orientation of the 2D emission dipoles of the quantum dot and the orientation of the symmetry axis of the nitrogen-vacancy center were calculated.…”

“…The inverse tangent function has a quadrant correction in the Euclidean plane, from which the following correction of the calculated in-plane angles are derived. If the conditions in equations ( 14) or ( 15) are true, the values of φx (14) or φy (15) need to be corrected as shown in equation ( 16) [7].…”

“…The successful calibration of the detection efficiency of an Si-SPAD using the single-photon emission of an InGaAs quantum dot has been shown recently [5,6]. Moreover, an analysis of the angular-dependent emission of NV-centers in nanodiamonds has been accomplished [7]. By using the knowledge about the angulardependent emission, advanced sample preparation techniques could be implemented to confine the emission into the direction of the microscope objective and subsequently reach a higher photon rate at the detector, allowing for an easier absolute calibration of SPAD detectors.…”

“…Furthermore, an analysis of the angular-dependent emission of core-shell CdSe/CdS quantum dots has been carried out using back focal plane imaging technique. The results are then compared with those reported in [7] for an NV-center in nanodiamond.…”