一种基于深刻蚀的硅基周期波导微腔

Silicon Photonic Crystal Nanobeam Cavities Fabricated by Deep-Etching Method

研究了一种基于深刻蚀的硅基周期波导一维光子晶体微腔,采用时域有限差分(FDTD)方法对设计的微腔结构进行了模拟分析;讨论了深刻蚀对微腔品质因数的影响,计算表明采用深刻蚀可有效地保持高Q值并能保证微腔的机械强度。采用电子束光刻(EBL)结合感应耦合等离子体(ICP)刻蚀制作了绝缘硅(SOI)的周期波导微腔,使用扫描电子显微镜(SEM)和原子力显微镜(AFM)对器件形貌进行表征,观察到深刻蚀的衬底二氧化硅高度约为80 nm。通过波导光栅耦合光纤输入宽带光源信号对微腔器件进行光学表征,传输光谱测试表明该深刻蚀微腔器件Q值达5×103,插入损耗小于-2 d B。该深刻蚀的硅基周期波导微腔可用于集成光传感器和片上波分复用滤波器等应用。

A silicon photonic crystal nanobeam caivity based on deep-etching method is presented. Using finite difference time domain （FDTD） method, the influence of deep- etching on the Q factor of nanobeam cavities is designed and analyzed. The calculated results show that the deep-etching scheme can keep the high-Q value close to the air-bridge peer, as well as robust mechanical strength. The devices are fabricated on silicon on insulator （SOI） platform using electron beam lithography （EBL） and inductively coupled plasma （ICP）. Scanning electron microscope （SEM） and atomic force microscope （AFM） are employed to characterize the morphology of the fabricated nanobeam cavities. The measured transmission spectra indicate that the Q factor of deeply- etched nanobeam cavities surpass 5 × 10^3 with acceptable insertion loss of less than - 2 dB. These deeply-etched nanobeam cavities can find their applications in on-chip optical sensors or optical filters.