Ever-increasing demands for a higher bandwidth of data in the optical communications augment the operating frequency of components and systems. To accelerate the development of these large-bandwidth technologies, there is a growing demand to characterize the frequency response of optical devices in real time. In this work, we report a method to significantly improve the measurement speed of an optical vector network analyzer (OVNA) with coherent time-stretch (CTS). Single-shot frequency spectrum measurements are enabled by time-stretch technology that maps the spectrum of an optical pulse to the time domain. Compared to single-ended detection, the implementation of coherent detection enables the acquiring of accurate phase information of the signal and also provides the digital processed cancellation of dispersion-induced impairments. By utilizing dispersive time-stretch and digital coherent detection techniques, we demonstrate an ultrafast and wide bandwidth OVNA. We successfully characterize its performance by measuring the frequency response of a micro-ring cavity and a silicon Mach–Zehnder interferometer with 0.07-nm spectral resolution and 0.156-rad phase accuracy over 10-nm bandwidth. Meanwhile, the dynamic responses of the magnitude and phase, and the drift of the resonance wavelength of the micro-ring modulator under thermal tuning, were fully recorded by the CTS-OVNA at a 20-MHz frame rate.

中文翻译：

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基于相干时间拉伸的超快单次光矢量网络分析仪

在光通信中对更高数据带宽的不断增长的需求增加了组件和系统的工作频率。为了加速这些大带宽技术的发展，越来越需要实时表征光学设备的频率响应。在这项工作中，我们报告了一种通过相干时间拉伸（CTS）显着提高光矢量网络分析仪（OVNA）的测量速度的方法。单次频谱测量是通过时延技术实现的，该技术将光脉冲的频谱映射到时域。相较于单端检测，相干检测的实现可以获取信号的准确相位信息，还可以对色散引起的损伤进行数字处理。通过利用色散时间拉伸和数字相干检测技术，我们演示了超快速和宽带OVNA。我们通过测量微环腔和硅马赫-曾德尔干涉仪的频率响应，在10 nm带宽上具有0.07 nm的光谱分辨率和0.156 rad的相位精度来成功表征其性能。同时，CTS-OVNA以20 MHz的帧速率完全记录了幅度和相位的动态响应以及在热调谐下微环调制器的谐振波长的漂移。在10nm带宽内具有07nm的光谱分辨率和0.156rad的相位精度。同时，CTS-OVNA以20 MHz的帧速率完全记录了幅度和相位的动态响应以及在热调谐下微环调制器的谐振波长的漂移。在10nm带宽内具有07nm的光谱分辨率和0.156rad的相位精度。同时，CTS-OVNA以20 MHz的帧速率完全记录了幅度和相位的动态响应以及在热调谐下微环调制器的谐振波长的漂移。