A scheme is proposed for measuring electron level populations in a semiconductor quantum dot embedded in a multimode waveguide. The photon transmittance of the waveguide under steady-state pumping is shown to depend on the presence of an electron in the ground state of the quantum dot. The influence of waveguide, quantum dot, and photon source parameters on the electron detection process is examined. It is shown that, even at a moderate mode Q-factor (10⁴ to 10⁵), the measurement contrast and signal-to-noise ratio are rather high (above 10⁴). The feasibility of using the proposed method for probing the state of a charge qubit is discussed.

中文翻译：

---

使用光波导测量量子点水平群体

提出了一种用于测量嵌入多模波导中的半导体量子点中的电子能级群体的方案。显示在稳态泵浦下波导的光子透射率取决于量子点基态中电子的存在。研究了波导、量子点和光子源参数对电子检测过程的影响。结果表明，即使在中等模式Q因子（10 ⁴至 10 ⁵）下，测量对比度和信噪比也相当高（高于 10 ⁴）。讨论了使用所提出的方法探测电荷量子比特状态的可行性。