Masuda Tamiko, Hadden J P E, Lake David P, Mitchell Matthew, Flågan Sigurd, Barclay Paul E
Opt Express. 2024 Feb 26;32(5):8172-8188. doi: 10.1364/OE.507325.
Fiber-coupled microdisks are a promising platform for enhancing the spontaneous emission from color centers in diamond. The measured cavity-enhanced emission from the microdisk is governed by the effective volume (V) of each cavity mode, the cavity quality factor (Q), and the coupling between the microdisk and the fiber. Here we observe room temperature photoluminescence from an ensemble of nitrogen-vacancy centers into high Q/V microdisk modes, which when combined with coherent spectroscopy of the microdisk modes, allows us to elucidate the relative contributions of these factors. The broad emission spectrum acts as an internal light source facilitating mode identification over several cavity free spectral ranges. Analysis of the fiber taper collected microdisk emission reveals spectral filtering both by the cavity and the fiber taper, the latter of which we find preferentially couples to higher-order microdisk modes. Coherent mode spectroscopy is used to measure Q ∼ 1 × 10 - the highest reported values for diamond microcavities operating at visible wavelengths. With realistic optimization of the microdisk dimensions, we predict that Purcell factors of ∼50 are within reach.
光纤耦合微盘是增强金刚石中色心自发发射的一个很有前景的平台。从微盘测量到的腔增强发射由每个腔模的有效体积（V）、腔品质因数（Q）以及微盘与光纤之间的耦合决定。在此，我们观察到室温下氮空位中心系综向高Q/V微盘模的光致发光，当与微盘模的相干光谱相结合时，这使我们能够阐明这些因素的相对贡献。宽发射光谱作为一种内部光源，有助于在几个腔自由光谱范围内识别模式。对光纤锥收集的微盘发射的分析揭示了腔和光纤锥的光谱滤波，我们发现后者优先耦合到高阶微盘模。相干模光谱用于测量Q ∼ 1×10⁴——这是在可见波长下运行的金刚石微腔所报道的最高值。通过对微盘尺寸进行实际优化，我们预测珀塞尔因子约为50是可以实现的。
