报道了单光子探测条件下的法拉第反常色散滤波器(FADOF)滤波特性的实验结果。测量结果表明,工作在D2共振线的Rb原子780 nm法拉第反常色散滤波器的翼谱透射率为28%,滤光带宽为0.7 GHz,以及最小可探测激光功率为0.16 pW/cm2。由于使用了单光子探测器测量法拉第反常色散滤波器物理参数的方法,极大地提高了实验测量的探测灵敏度。通过实验数据分析,给出了相关的讨论。在日光情况下,如果使用这种780 nm Rb法拉第反常色散滤波器代替干涉滤波片,将极大地降低背景光噪声和减少误码率,使得在单光子水平的激光通信更接近于实用。

A 780 nm Rb Faraday atomic dispersive optical filter (FADOF) that operates in the wings of Rb D2 resonance line is experimentally studied with a single photon detector. The measure result shows that the maximum transmission of the 780nm Rb FADOF is 28% and the full width at half maximum is 0.7 GHz. A minimum detectable laser power of 0.16 pW/cm2 is obtained with the signal-to-noise ratio of transmission spectrum of 2. Therefore, the detection sensitivity of Rb FADOF is remarkably increased when a single photon detector is used. If the Rb FADOF is used to replace a interferential optical filter in laser communication, it can lead to a lower bit error ratio and the system that operates with single photon detector is able to work during daytime when optical background is much larger.