Habif Jonathan L, Jagannathan Arunkumar, Gartenstein Samuel, Amory Phoebe, Guha Saikat
Opt Express. 2021 Mar 1;29(5):7418-7427. doi: 10.1364/OE.417989.
Understanding the fundamental sensitivity limit of an optical sensor requires a full quantum mechanical description of the sensing task. In this work, we calculate the fundamental (quantum) limit for discriminating between pure laser light and thermal noise in a photon-starved regime. The Helstrom bound for discrimination error probability for single mode measurement is computed along with error probability bounds for direct detection, coherent homodyne detection and the Kennedy receiver. A generalized Kennedy (GK) receiver is shown to closely approach the Helstrom limit. We present an experimental demonstration of this sensing task and demonstrate a 15.4 dB improvement in discrimination sensitivity over direct detection using a GK receiver and an improvement of 19.4% in error probability over coherent detection.
要理解光学传感器的基本灵敏度极限，需要对传感任务进行完整的量子力学描述。在这项工作中，我们计算了在光子匮乏 regime 中区分纯激光和热噪声的基本（量子）极限。计算了单模测量的鉴别误差概率的赫尔斯托姆界以及直接检测、相干零差检测和肯尼迪接收器的误差概率界。结果表明，广义肯尼迪（GK）接收器非常接近赫尔斯托姆极限。我们给出了这项传感任务的实验演示，并证明使用GK接收器时，鉴别灵敏度比直接检测提高了15.4 dB，误差概率比相干检测提高了19.4%。
