Bright off-axis directional emission with plasmonic corrugations

Area of Science:

• Optics and Photonics
• Materials Science
• Quantum Technologies

Background:

• Diamond nitrogen vacancy (NV) centers are promising quantum emitters.
• Efficient light extraction is crucial for NV center applications.
• Plasmonic nanostructures offer enhanced light-matter interactions.

Purpose of the Study:

• To introduce a new plasmonic bulls-eye structure for enhanced light harvesting from diamond NV centers.
• To investigate the effect of a metal sub-layer on spontaneous emission and light out-coupling.
• To explore asymmetric structures for two-axis beam steering.

Main Methods:

• Design and simulation of a plasmonic bulls-eye antenna with a metal sub-layer and dielectric spacer.
• Analysis of Purcell factor and spontaneous emission enhancement.
• Investigation of far-field intensity enhancement compared to conventional structures.
• Study of asymmetric bulls-eye structures for beam steering.

Main Results:

• The proposed structure significantly enhances spontaneous emission and out-coupled light intensity.
• A three-fold increase in far-field intensity was observed compared to conventional structures.
• Asymmetric structures enable spatial off-axial steering over a cone.
• Steered light maintained high intensity, exceeding conventional symmetric structures, with directivity up to 16.

Conclusions:

• The novel plasmonic bulls-eye structure with a metal sub-layer is highly effective for enhancing light extraction from diamond NV centers.
• The design offers a high Purcell factor, boosting radiated light intensity.
• Asymmetric structures provide a new pathway for controlled two-axis beam steering with high directivity, opening possibilities for advanced optical devices.