Xiao M, Wu L A, Kimble H J
Opt Lett. 1988 Jun 1;13(6):476-8. doi: 10.1364/ol.13.000476.
An improvement in precision beyond the limit set by the vacuum-state or zero-point fluctuations of the electromagnetic field is reported for the detection of amplitude modulation encoded on a weak signal beam. The improvement is achieved by employing the squeezed light from an optical parametric oscillator to reduce the level of fluctuations below the shot-noise limit. An increase in signal-to-noise ratio of 2.5 dB relative to the shot-noise limit is demonstrated.
据报道，在检测弱信号光束上编码的振幅调制时，精度得到了提高，超出了由电磁场的真空态或零点涨落所设定的极限。这种提高是通过使用光学参量振荡器产生的压缩光，将涨落水平降低到散粒噪声极限以下来实现的。相对于散粒噪声极限，信噪比提高了2.5分贝。
