We demonstrate a high responsivity all-silicon in-line optical power monitor by using the thermal effect to enhance the quantum efficiency of defect-mediated absorption at 1550 nm. The doping compensation technique is utilized to increase the density of lattice defects responsible for the sub-bandgap absorption and suppress the detrimental free carrier absorption. The 200-μm-long device presents a propagation loss as low as 2.9 dB/cm. Its responsivity is enhanced from 12.1 mA/W to 112 mA/W at $-9\mathrm{V}$ bias by heating the optical absorption region. With this device, we build an optical power monitoring system that operates in the sampling mode. The minimal detectable optical power of the system is below $-22.8\mathrm{dBm}$, while the average power consumption is less than 1 mW at a sampling frequency of 10 Hz. Advantages of this scheme in terms of high responsivity, low insertion loss, and low power consumption lend itself to implement the feedback control of advanced large-scale silicon photonic integrated circuits.

中文翻译：

---

基于缺陷介导吸收的全硅光功率监视器中的热增强响应率

我们通过使用热效应来提高 1550 nm 处缺陷介导吸收的量子效率，展示了一种高响应度全硅在线光功率监测器。掺杂补偿技术用于增加负责亚带隙吸收的晶格缺陷的密度并抑制有害的自由载流子吸收。200 微米长的设备呈现低至 2.9 dB/cm 的传播损耗。其响应度从 12.1 mA/W 提高到 112 mA/W$-9\mathrm{伏}$通过加热光吸收区来偏置。使用该设备，我们构建了一个在采样模式下运行的光功率监控系统。系统的最小可检测光功率低于$-22.8\mathrm{分贝}$，而在 10 Hz 的采样频率下平均功耗小于 1 mW。该方案在高响应度、低插入损耗和低功耗方面的优势有助于实现先进的大规模硅光子集成电路的反馈控制。