Chen Liao, Duan Yuhua, Zhang Chi, Zhang Xinliang
Opt Lett. 2017 Jul 15;42(14):2726-2729. doi: 10.1364/OL.42.002726.
We propose and experimentally demonstrate a new type of all-optical radio frequency (RF) spectrum analyzer based on temporal convolution and cross-phase modulation (XPM) that can be regarded as the frequency-domain counterpart of a conventional light intensity spectrum analyzer (LISA). The XPM effect converts the intensity envelope of an optical signal to the phase of the probe signal, while the temporal convolution helps to enable the RF spectrum to be temporally resolved with a high frame rate. This frequency-domain LISA (f-LISA) has experimentally demonstrated an 800-GHz observation bandwidth with 1.25-GHz resolution (1 GHz for a single frequency) and a 94-MHz frame rate. To showcase its potential applications, this analyzer has successfully characterized the dynamic RF spectrum of an ultrafast wavelength-switching signal with a 10-ns switching interval. We believe that it is promising for some ultrafast dynamic RF spectrum acquisition applications, e.g., fast tuning lasers and real-time channel monitoring.
我们提出并通过实验证明了一种基于时间卷积和交叉相位调制（XPM）的新型全光射频（RF）频谱分析仪，它可被视为传统光强度频谱分析仪（LISA）在频域的对应物。XPM效应将光信号的强度包络转换为探测信号的相位，而时间卷积有助于以高帧率在时间上分辨RF频谱。这种频域LISA（f-LISA）已通过实验证明具有800GHz的观测带宽，分辨率为1.25GHz（单频为1GHz），帧率为94MHz。为了展示其潜在应用，该分析仪成功地对具有10ns切换间隔的超快波长切换信号的动态RF频谱进行了表征。我们认为它在一些超快动态RF频谱采集应用中具有前景，例如快速调谐激光器和实时信道监测。
