A Faraday fiber-optic current sensor with suppression of excess noise produced by a low-coherent light source is presented. The sensor is designed to detect short current pulses and represents an in-line interferometer with a sensing element based on a spun highly birefringent fiber. To suppress the excess noise, a two-channel light detection scheme without an additional delay line is applied. It is established that bending birefringence induced in the spun fiber wound on a coil limits the noise suppression. To minimize this effect, a new geometry of the sensing coil is used. The proposed sensor exhibits a 5-fold improvement of the signal-to-noise ratio and the same enhancement of the sensitivity to a value of 0.8A in the 3.5 MHz bandwidth. The minimum duration of the measured current pulse is 200 ns.

提出了一种法拉第光纤电流传感器，该传感器可抑制由低相干光源产生的过量噪声。该传感器设计用于检测短电流脉冲，并代表一种带干涉的在线干涉仪，该感测器基于旋转的高双折射光纤。为了抑制过多的噪声，采用了没有额外延迟线的两通道光检测方案。已经确定，在缠绕在线圈上的纺丝纤维中引起的弯曲双折射会限制噪声抑制。为了使这种影响最小化，使用了感应线圈的新几何形状。所提出的传感器在3.5 MHz带宽中的信噪比提高了5倍，灵敏度也提高到了0.8A。被测电流脉冲的最小持续时间为200 ns。