Characteristics of optical bandpass filters employing series-cascaded double-ring resonators

• DOI: 10.1016/j.optcom.2003.09.092
• Publication Date: 2003-10-22T12:21:15Z
• Authors: Jianyi Yang; Qingjun Zhou; Feng Zhao; Xiaoqing Jiang; Brie Howley; Minghua Wang; Ray T Chen
• Keywords: 0202 electrical engineering, electronic engineering, information engineering; 02 engineering and technology

The filtering characteristics of a series-cascaded double-ring optical resonator (SDRR) are investigated. The roles of coupling coefficients and the effects of optical loss are analyzed. The relationships of the coupling coefficients with the characteristics of the SDRR filter are expressed with simple analytical formulas. With the derived approximate formulas, it is found that the bandwidth ratio of the SDRR filter is mainly dependent on the shape factor defined in this paper. The performance of the SDRR filter, especially the bandwidth ratio, is improved significantly in comparison with that of the single-ring-resonator filter. The analytical results also indicate that the optical loss in the microrings has a strong influence on the characteristics of the SDRR filter.