Fig. 3.

Nanophotonic integration of group IV emitters. Photonic crystals containing group IV diamond colour centres and including: a 1D triangular nanobeam cavities (from ref. ⁵⁶. Reprinted with permission from AAAS). b Quasi-isotropic etched nanobeams (from ref. ⁸⁵. Reprinted with permission from AAAS). c FIB-patterned diamond membranes (figure reproduced with permission from ref. ⁸⁶. Copyright 2012, Springer Nature). d Fibre-microcavity integrated SiV^– centres (reproduced with permission from ref. ⁸⁷. Copyright 2017 by the American Physical Society). e GeV^– centres coupled to micro-rings (reproduced with permission from ref. ⁸⁸. American Chemical Society). f Group IV strain tuning devices based on electrostatically actuated cantilevers (reprinted with permission from ref. ⁸⁹. Copyright 2018 by the American Physical Society). g Optical properties of SiV^– centres in 1D photonic structures. The linewidth distribution shows near-lifetime-limited SiV^– centres in optical structures (reprinted with permission from ref. ²⁶. Copyright 2016 by the American Physical Society). h Cavity reflectivity measurements indicating a high cooperativity C > 20 (from ref. ⁸⁵. Reprinted with permission from AAAS).