Abstract. A scheme for detecting the phase of an incoming optical signal is systematically optimized and demonstrated experimentally. It makes use of four-wave mixing in a highly nonlinear fiber but differs from a phase-sensitive amplifier by its focus on phase detection, rather than on phase-dependent noise reduction. This experimental setup combines the signal with its phase-conjugated idler at the same frequency, before sending the combination to a photodetector. Experimental results show that the ratio of maximum and minimum currents can exceed 1000 even at a relatively low pump power of 10 mW. The proposed scheme may be useful for detecting the signal phase in coherent communication systems without the need of heterodyne detection.

中文翻译：

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通过光纤中的四波混频进行相位检测

摘要。一种用于检测输入光信号相位的方案被系统地优化和实验证明。它在高度非线性的光纤中使用四波混频，但与相敏放大器的不同之处在于它侧重于相位检测，而不是与相位相关的降噪。该实验装置将信号与其相位共轭闲散光以相同的频率组合在一起，然后将组合发送到光电探测器。实验结果表明，即使在 10 mW 的相对较低的泵浦功率下，最大和最小电流之比也可以超过 1000。所提出的方案可用于在不需要外差检测的情况下检测相干通信系统中的信号相位。