Defect modes in microring resonator arrays fabricated in silicon-on-insulator technology

Abstract-We show experimentally the existence of defect modes in mutually coupled microring resonator array fabricated in silicon-on-insulator technology. The movements of donor-like and acceptor-like modes are demonstrated for various defect lengths and in a good agreement with earlier theoretical prediction. Microring resonator is an integrated-optic form of Fabry-Perot etalon that is capable of realizing various active and passive functionalities, such as filters, lasers, sensors, and switches. These functionalities can be further extended by integrating these resonators in array geometries for slow light structure [1, 2] and high order filters [3-5]. In periodic array geometries consisting of identical rings, there exists a frequency band within which the light is not allowed to propagate inside the structure. This is called a photoni