Jiang Xinhong, Yang Zhifang, Liu Zexu, Dang ZhangQi, Ding Zhenming, Chang Qing, Zhang Ziyang
Opt Express. 2021 Jan 18;29(2):2090-2098. doi: 10.1364/OE.414827.
We present a 3D integrated wavelength demultiplexer using a square-core fiber (SCF) and matched dual-layer arrayed waveguide gratings (AWGs). The SCF works as a 3D fiber multimode interference device, which splits the input light into symmetric four spots. The spots are then coupled to a pitch-matched 4-waveguide network, each connecting an AWG. Interface waveguides are designed to improve the coupling efficiency between the SCF and the dual-layer chip. The four AWGs are designed with different central wavelengths and a large free spectral range (FSR) of 120 nm. To reach a small and uniform insertion loss among different channels, only the central channels of each AWG are used for demultiplexing. The device is fabricated on a polymer platform. The upper and lower layers of the chip are fabricated using the same photolithography mask but rotated 180° so that 4 different AWG designs can be mapped to a single chip. The measured transmission spectra of the four AWGs cover a bandwidth of 112 nm. The insertion loss variation is smaller than 1.4 dB. The designed device can find applications in fiber optic sensing, communication, and astronomy.
我们展示了一种使用方形芯光纤（SCF）和匹配的双层阵列波导光栅（AWG）的三维集成波长解复用器。SCF用作三维光纤多模干涉器件，将输入光分成对称的四个光斑。然后将这些光斑耦合到间距匹配的四波导网络，每个波导连接一个AWG。设计了接口波导以提高SCF与双层芯片之间的耦合效率。四个AWG设计有不同的中心波长和120 nm的大自由光谱范围（FSR）。为了在不同通道之间实现小且均匀的插入损耗，仅使用每个AWG的中心通道进行解复用。该器件在聚合物平台上制造。芯片的上层和下层使用相同的光刻掩模制造，但旋转180°，以便将4种不同的AWG设计映射到单个芯片上。四个AWG的测量传输光谱覆盖112 nm的带宽。插入损耗变化小于1.4 dB。所设计的器件可应用于光纤传感、通信和天文学领域。
