Reduction of Wavelength Dependence of Coupling Characteristics Using Si Optical Waveguide Curved Directional Coupler
Reduction of Wavelength Dependence of Coupling Characteristics Using Si Optical Waveguide Curved Directional Coupler
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DOI：
10.1109/jlt.2014.2321660
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发表时间：
2014-06-15
影响因子：
4.7
通讯作者：
Iiyama, Koichi
中科院分区：
文献类型：
--
作者：
Morino, Hisayasu;Maruyama, Takeo;Iiyama, Koichi
定向耦合器作为光集成电路的关键器件之一，得到了广泛的应用。然而，常规定向耦合器的耦合效率对波长高度敏感。这种灵敏度降低了包含用于波分复用传输的定向耦合器的器件的特性。提出了一种利用石英光波导作为耦合器之一的弯曲定向耦合器，该耦合器具有波长不敏感、占用空间小、易于加工等优点。本文从理论上研究了这种硅线波导弯曲耦合器，结果表明，弯曲半径为21 μ m，耦合长度为7.40 μ m的弯曲耦合器，在透射率变化范围为-3 +/-0.1dB内，与普通定向耦合器相比，可以减小波长依赖性，使工作带宽提高约7倍。
Directional couplers are widely used as one of the key components of optical integrated circuits. However, the coupling efficiency of the conventional directional coupler is highly sensitive to wavelength. This sensitivity degrades the characteristics of devices that contain directional couplers for wavelength division multiplexing transmission. A curved directional coupler has been proposed using silica optical waveguide as one of the coupler which realize wavelength insensitive, small footprint and tolerant to fabrication. In this paper, we theoretically investigated this curved coupler using Si wire waveguide and got results that the curved coupler whose bending radius of 21 mu m and coupling length of 7.40 mu m can reduce the wavelength dependence and achieve about a sevenfold enhancement of operational bandwidth in the transmittance variation range of -3 +/- 0.1 dB compared with conventional directional coupler.