In this letter, a wavelength-tunable Optical Time-Domain Reflectometer (OTDR) for Dense Wavelength Division Multiplexing Passive Optical Network (DWDM-PON) is proposed and experimentally demonstrated. An Integrated Tunable Laser Assembly (ITLA) serves as the light source permitting measurements of 80 DWDM channels in the C-band. Dither modulation is added to ITLA to depress coherent noise resulted from the narrow linewidth of the light source. Semiconductor Optical Amplifier (SOA) modulates the continuous light into pulsed light and meanwhile amplifies peak optical power of the pulsed light to 13 dBm. In addition, we optimize the wavelet denoising algorithm for further signal-noise ratio (SNR) enhancement. Dynamic range and spatial resolution of the proposed OTDR reach up to 16.2 dB and 2 m respectively. A DWDM-PON fiber link including an Arrayed Waveguide Grating (AWG) is measured to verify the system performances, and the OTDR profiles of different channels coincide with each other. The designed wavelength-tunable OTDR is shown to be appropriate for DWDM-PON.

中文翻译：

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基于优化小波去噪的 DWDM-PON 波长可调谐 OTDR


在这封信中，提出了一种用于密集波分复用无源光网络（DWDM-PON）的波长可调谐光时域反射计（OTDR）并进行了实验演示。集成可调谐激光组件 (ITLA) 用作光源，允许测量 C 波段中的 80 个 DWDM 通道。 ITLA 中添加了抖动调制，以抑制光源线宽较窄所产生的相干噪声。半导体光放大器（SOA）将连续光调制为脉冲光，同时将脉冲光的峰值光功率放大至13dBm。此外，我们还优化了小波去噪算法以进一步增强信噪比（SNR）。所提出的 OTDR 的动态范围和空间分辨率分别达到 16.2 dB 和 2 m。通过测量包含阵列波导光栅 (AWG) 的 DWDM-PON 光纤链路来验证系统性能，不同通道的 OTDR 曲线相互吻合。设计的波长可调谐 OTDR 被证明适用于 DWDM-PON。