Two-dimensional transition-metal dichalcogenides (TMDC) are of great interest for on-chip nanophotonics due to their unique optoelectronic properties. Here, we propose and realize coupling of tungsten diselenide (WSe) monolayers to circular Bragg grating structures to achieve enhanced emission. The interaction between WSe and the resonant mode of the structure results in Purcell-enhanced emission, and the symmetric geometrical structure improves the directionality of the out-coupling stream of emitted photons. Furthermore, this hybrid structure produces a record high contrast of the spin valley readout (>40%) revealed by the polarization-resolved photoluminescence (PL) measurements. Our results are promising for on-chip integration of TMDC monolayers with optical resonators for nanophotonic circuits.
KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The authors are thankful for financial support from the Australian Research council (via DP180100077, DE180100070, DE 1801100810), the Asian Office of Aerospace Research and Development grant FA2386-17-1-4064, the Office of Naval Research Global under grant number N62909-18-1-2025, National Key R & D Program of China (Grants No. 2018YFA0306100), the National Natural Science Foundation of China (Grant No. 11874437), Guangzhou Science and Technology project (Grant No. 201805010004). This research is supported by an Australian Government Research Training Program Scholarship.