Enhanced single-photon emissions from NV centers in nanodiamonds by a simple plasmonic hybrid structure
Chia-Wei Chang1*, Yen-Chun Chen1, Jer-Shing Huang2, Wen-Hao Chang1
1Electrophysics, National Chiao Tung University, Hsinchu, Taiwan
2Chemistry, National Tsing Hua Unversity, Hsinchu, Taiwan
* presenting author:chia wei chang, email:wxes60704@yahoo.com.tw
Nitrogen-vacancy (NV) color center [1] in nanodiamonds (NDs) is known as the most stable single-photon source at room temperature. For practical applications in quantum information technology, optimized emission and collection efficiencies of single photons are prerequisites. Coupling of ND emissions into photonic microcavities, waveguides or surface plasmon resonance [2] has been proposed and demonstrated to tackle this problem. In order to reach better overlap between NV centers and plasmonic fields, we propose a new plasmonic hybrid structure consisting of nanodiamonds embedded in a spin-on glass (SOG) [3] layer on a single-crystalline Au flakes and covered by a TiO2 layer. The hybrid plasmonic structure features a strong localization of plasmonic field in the SOG layer, which can greatly enhance the fluorescence intensity from the NV centers. To achieve a better plasmonic field confinement, the thickness of the SOG layer is an important parameter. By fabricating the TiO2 layer into different geometries, different kind of plasmonic devices, such as cavities, waveguides and antennas can be integrated on the same platform for practical applications based on the hybrid plasmonic structure.

[1] Christian Kurtsiefer et al, PhysRevLett.85.290 (2000)
[2] H. Raether, Surface Plasmons (Springer, New York, 1988)
[3] Yu-Jung Lu et al, Science 337, 450 JULY (2012)

Keywords: Plasmonic structure, Nanodiamonds, Nitrogen-vacancy (NV) center, Surface plasma