Enhanced Extraction of Silicon-Vacancy Centers Light Emission Using Bottom-Up Engineered Polycrystalline Diamond Photonic Crystal Slabs

Silicon vacancy (SiV) centers are optically active defects in diamond. The SiV centers, in contrast to nitrogen vacancy (NV) centers, possess narrow and efficient luminescence spectrum (centered at ≈738 nm) even at room temperature, which can be utilized for quantum photonics and sensing applications. However, most of light generated in diamond is trapped in the material due to the phenomenon of total internal reflection. In order to overcome this issue, we have prepared two-dimensional photonic crystal slabs from polycrystalline diamond thin layers with high density of SiV centers employing bottom-up growth on quartz templates. We have shown that the spectral overlap between the narrow light emission of the SiV centers and the leaky modes extracting the emission into almost vertical direction (where it can be easily detected) can be obtained by controlling the deposition time. More than 14-fold extraction enhancement of the SiV centers photoluminescence was achieved compared to an uncorrugated sample. Computer simulation confirmed that the extraction enhancement originates from the efficient light-matter interaction between light emitted from the SiV centers and the photonic crystal slab.

In the figure at the top left is a sketch of a photonic structure in a section. Below it is a picture of a 2D photonic crystal produced by a scanning electron microscope. In the middle is the so-called band structure of light modes of a given structure, demonstrating the existence of a mooring channel at 738 nm. On the right is a comparison of the photoluminescence spectrum of a 2D photonic crystal and a planar reference showing a 14-fold increase in the photoluminescence signal intensity at 738 nm.

¹Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, 162 00 Prague 6, Czech Republic
²Faculty of Electrical Engineering, Czech Technical University in Prague, Technická 2, CZ-166 27, Prague 6, Czech Republic
³J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, v.v.i., Dolejškova 3, CZ-182 23, Prague 8, Czech Republic