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 (WSe2) monolayers to circular Bragg grating structures to achieve enhanced emission. The interaction between WSe2 and the resonant mode of the structure results in Purcell-enhanced emission, while 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.
@article{arxiv.1806.06515,
title = {Enhanced Emission from WSe2 Monolayers Coupled to Circular Bragg Gratings},
author = {Ngoc My Hanh Duong and Zai-Quan Xu and Mehran Kianinia and Rongbin Su and Zhuojun Liu and Sejeong Kim and Carlo Bradac and Lain-Jong Li and Alexander Solntsev and Jin Liu and Igor Aharonovich},
journal= {arXiv preprint arXiv:1806.06515},
year = {2018}
}