High-resolution and high-sensitivity optical vector analysis (OVA) is highly desired by many applications, such as optical sensors and photonic integrated circuits (PICs). However, it is difficult to achieve high resolution and high sensitivity simultaneously. Here, we propose and experimentally demonstrate a high sensitivity OVA using coherent detection to achieve the complex frequency responses (including magnitude and phase responses) of a device under test (DUT). Carrier phase noise (CPN) cancellation is employed to eliminate the carrier phase fluctuation induced by the coherent detection. In an experiment, the frequency responses of a fiber Bragg grating (FBG) is accurately measured by the proposed method when the probe light is suppressed by ~18 dB. As a comparison, the method using coherent detection without CPN cancellation can only achieve the magnitude response, and the method using direct detection cannot obtain an effective measurement. The influence of the linewidth and time delay on the measurement is discussed. The proposed OVA provides a stable, high resolution, high sensitivity and low cost approach for characterizing optical devices with arbitrary response, especially for optical devices with large loss or bandpass response.

中文翻译：

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具有增强灵敏度的高分辨率光学矢量分析


光学传感器和光子集成电路 (PIC) 等许多应用都非常需要高分辨率和高灵敏度光学矢量分析 (OVA)。然而，同时实现高分辨率和高灵敏度是很困难的。在这里，我们提出并通过实验演示了一种使用相干检测的高灵敏度 OVA，以实现被测设备 (DUT) 的复杂频率响应（包括幅度和相位响应）。采用载波相位噪声（CPN）消除来消除相干检测引起的载波相位波动。在实验中，当探测光被抑制约 18 dB 时，所提出的方法可以准确测量光纤布拉格光栅 (FBG) 的频率响应。相比之下，使用相干检测而不进行CPN消除的方法只能实现幅度响应，而使用直接检测的方法无法获得有效的测量。讨论了线宽和时延对测量的影响。所提出的 OVA 为表征具有任意响应的光学器件，特别是具有大损耗或带通响应的光学器件提供了一种稳定、高分辨率、高灵敏度和低成本的方法。