We experimentally demonstrate two types of silicon-on-insulator microring devices: 1) a slotted conventional microring resonator (MRR) using a multimode interferometer (MMI) coupler as the coupling element; and 2) an MMI-coupled slotted Mach-Zehnder interferometer (MZI) racetrack microring. We achieved a high bandwidth of 1.1 nm and a quality factor Q of ∼ 1300 at the wavelength of 1510 nm for the conventional MRRs with a radius of 20 μ. A high extinction ratio (17-25 dB) is exhibited over a wavelength range from 1490 to 1520 nm. At the 1515-nm resonance wavelength, the MMI-coupled MZI racetrack microring demonstrates a quasi-free spectral range of 22.6 nm with a high extinction ratio of 25 dB. The demonstrated devices have many applications such as biochemical and gas sensing and modulation in communication systems.

Microring resonators, MMI, MZI, silicon on insulator, slot waveguides
IEEE Photonics Technology Letters
Department of Electronics

Xiong, Y. (Yule), & Ye, W.N. (2013). Silicon MMI-coupled slotted conventional and MZI racetrack microring resonators. IEEE Photonics Technology Letters, 25(19), 1885–1888. doi:10.1109/LPT.2013.2279121