Stimulated emission depletion, or STED microscopy, is a well-established super-resolution technique, but is ultimately limited by the chosen fluorophore. Here we demonstrate STED microscopy with color centers in nanoscale flakes of hexagonal boron nitride using time-gated, continuous-wave STED. For color centers with zero phonon line emission around 580 nm, we measure a STED cross section of (5.5 ± 3.2) × 10^–17 cm², achieve a resolution of ∼50 nm, and resolve two color centers separated by 250 nm, which is less than the diffraction limit. The achieved resolution is limited by the numerical aperture of the objective lens (0.8) and the available laser power, and we predict that a resolution of sub-10 nm can be achieved with an oil immersion objective lens, similar to the state-of-the-art resolution obtained with nitrogen vacancy centers in diamond.

中文翻译：

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六方氮化硼色心受激发射损耗显微术

受激发射损耗或 STED 显微镜是一种成熟的超分辨率技术，但最终受到所选荧光团的限制。在这里，我们使用时间门控、连续波 STED 展示了在六方氮化硼纳米级薄片中具有色心的 STED 显微镜。对于在 580 nm 附近具有零声子线发射的色心，我们测量了 (5.5 ± 3.2) × 10 ^–17 cm ²的 STED 横截面，实现~50 nm 的分辨率，并解析两个相距 250 nm 的色心，这小于衍射极限。实现的分辨率受物镜数值孔径 (0.8) 和可用激光功率的限制，我们预测使用油浸物镜可以实现亚 10 nm 的分辨率，类似于用金刚石中的氮空位中心获得的最先进的分辨率。