论文标题
腔参数估计的正交平均同源性检测
Quadrature-averaged homodyne detection for cavity parameter estimation
论文作者
论文摘要
平衡同源干涉法是一种众所周知的检测技术，可实现光场的敏感表征。通常，通过主动反馈环将参考光束与信号梁的相对相锁定与信号光束的相对相位，可以操作一个同源的干涉仪。一种不太常用的方法是对参考梁臂长度进行缓慢的连续调节，该调制与测量过程中的所有相对相对应。在这里，我们在理论上和实验上显示，这种正交平均对于估计共振光腔的参数可能是有利的。我们证明，平均值将转导函数从腔频率波动转变为干涉仪信号，转变为激光的简单函数，尤其是该激光器不依赖于系统中存在的非谐振通道的参数。该方法不需要主动的反馈，并且可以提供易于解释的结果。此外，相平均测量值可以表征腔频率调制的绝对幅度。
Balanced homodyne interferometry is a well-known detection technique that allows for sensitive characterization of light fields. Conventionally a homodyne interferometer is operated by locking the relative phase of a reference beam to the signal beam by means of an active feedback loop. A less often used method is to perform a slow continuous modulation of the reference beam arm length that corresponds to averaging all relative phases during the measurement.Here we show theoretically and experimentally that this quadrature averaging can be advantageous in estimating the parameters of a resonant optical cavity. We demonstrate that the averaging turns the transduction function, from cavity frequency fluctuations into the interferometer signal, into a simple function of the laser detuning that, notably, does not depend on the parameters of possible non-resonant channels present in the system. The method needs no active feedback and gives results that are easy to interpret. Moreover, the phase-averaged measurement allows to characterize the absolute magnitude of a cavity frequency modulation.
