As a result of its indirect bandgap, emitting photons from silicon in an efficient way remains challenging. Silicon light emitters that can be integrated seamlessly on a CMOS platform have been demonstrated; however, none satisfies an ensemble of key requirements such as a small footprint, room-temperature operation at low voltages, and emission of narrow and polarized lines with a high spectral power density in the near-infrared range. Here, we present an all-silicon electrically driven light emitting diode that consists of an inversely tapered half-ellipsoidal silicon photonic resonator containing a p–n junction used to excite whispering gallery modes (WGMs) inside the resonator. Under low voltage operation at room temperature, such a photonic silicon light-emitting diode exhibits a band-edge emission (900–1300 nm) with a wall-plug efficiency of 10−4. The emitted spectrum is amplified in multiple WGMs and shows peaks that are polarized and have linewidths Δλ as narrow as 0.33 nm and spectral power densities as high as 8 mW cm−2 nm−1. Considering its small footprint of ∼1 µm and remarkable emission characteristics, this silicon light source constitutes a significant step ahead toward fully integrated on-chip silicon photonics.

中文翻译：

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基于反锥形光子谐振器中电激发回音壁模式的全硅偏振光源

由于其间接带隙，以有效的方式从硅发射光子仍然具有挑战性。可以在 CMOS 平台上无缝集成的硅光发射器已经得到展示；然而，没有一个能满足一系列关键要求，例如小尺寸、低电压室温操作以及在近红外范围内发射具有高光谱功率密度的窄极化线。在这里，我们提出了一种全硅电驱动发光二极管，它由一个包含 ap-n 结的倒锥形半椭球硅光子谐振器组成，用于激发谐振器内的回音壁模式 (WGM)。在常温低电压下工作，这种光子硅发光二极管表现出带边发射（900-1300 nm），壁插效率为 10-4。发射的光谱在多个 WGM 中被放大，并显示出偏振峰，线宽 Δλ 窄至 0.33 nm，光谱功率密度高达 8 mW cm-2 nm-1。考虑到其约 1 µm 的小尺寸和卓越的发射特性，这种硅光源是朝着完全集成的片上硅光子学迈出的重要一步。