标题： 同频检测的操作理论 显示英文标题

标题： Operational Theory of Homodyne Detection

摘要： 我们讨论在量子测量的操作方法框架下，使用不完美探测器的平衡外差检测方案。 我们表明，现实的外差测量由一组操作可观测量描述，该集合依赖于实验装置，而不是单个场分量算符。 我们找到了这一集合的显式形式，它完全表征了实验装置，并且与被测系统的特定状态无关。 我们还推导了具有随机相位的装置的操作外差可观测量，该装置最近已被应用于脉冲二极管激光器光子统计的超快测量。 操作公式直接给出了检测噪声与被测场内在量子涨落之间的关系。 我们通过两个例子来演示这一点：场分量的操作不确定性关系，以及光子统计中被抑制涨落的外差检测。 显示英文摘要

摘要： We discuss a balanced homodyne detection scheme with imperfect detectors in the framework of the operational approach to quantum measurement. We show that a realistic homodyne measurement is described by a family of operational observables that depends on the experimental setup, rather than a single field quadrature operator. We find an explicit form of this family, which fully characterizes the experimental device and is independent of a specific state of the measured system. We also derive operational homodyne observables for the setup with a random phase, which has been recently applied in an ultrafast measurement of the photon statistics of a pulsed diode laser. The operational formulation directly gives the relation between the detected noise and the intrinsic quantum fluctuations of the measured field. We demonstrate this on two examples: the operational uncertainty relation for the field quadratures, and the homodyne detection of suppressed fluctuations in photon statistics.