Department of Electrical and Computer Engineering, McGill University, H3A 2A7, Montreal, Quebec, Canada.
Opt Lett. 2010 Jun 1;35(11):1850-2. doi: 10.1364/OL.35.001850.
The second-order correlation function of incoherent light, which is usually measured in the time domain, can be alternatively measured in the frequency domain. Here, we use an all-optical technique in a highly nonlinear fiber for measuring the full spectrum of the fluctuations of the photocurrent (rf spectrum) generated by broadband radiation with different spectral coherence properties. Our experiments reveal that the rf spectrum of a light signal depends strongly on its spectral coherence properties. From a practical perspective, this ultrafast technique constitutes an alternative for measuring the intensity correlations of spectrally incoherent radiation.
非相干光的二阶相关函数通常在时域中测量，也可以在频域中测量。在这里，我们在高非线性光纤中使用全光技术测量由具有不同光谱相干特性的宽带辐射产生的光电流（射频谱）的波动的全光谱。我们的实验表明，光信号的射频谱强烈依赖于其光谱相干特性。从实际的角度来看，这种超快技术构成了测量光谱非相干辐射强度相关性的替代方法。
