,Design and Fabrication of Polarization-Independent Micro-Ring Resonators

• 作 者: GENG Min-Ming JIA Lian-Xi ZHANG Lei LIU Yu-Liang YANG Lin LI Fang
• 机 构: Laboratory on Optoelectronic Systems, Institute of Semiconductors, Chinese Academy of Sciences, PO B
• 出 处: 中国物理快报（英文版）
• 发表日期: 2008年4期

Origin of polarization sensitivity of photonic wire waveguides (PWWs) is analysed and the effective refractive indices of two different polarization states are calculated by the three-dimensional fall-vector beam propagation method. We find that PWWs are polarization insensitive if the distribution of its refractive index is uniform and the cross section is square. An MRR based on such a polarization-insensitive PWW is fabricated on an S-inch silicon-on-insulator wafer using 248-nm deep ultraviolet lithography and reactive ion etching. The quasi-TE mode is resonant at 1542.25nm and 1558.90nm, and the quasi-TM mode is resonant at 1542.12nm and 1558.94 nm.The corresponding polarization shift is 0.13 nm at the shorter wavelength and 0.04 nm at the longer wavelength.Thus the fabricated device is polarization independent. The extinction ratio is larger than lOdB. The 3dB bandwidth is about 2.5nm and the Qvalue is about 620 at 1558.90nm.