Low-loss photonic wires and compact ring resonators in silicon-on-insulator

We demonstrate low-loss, single-mode photonic wires in silicon-on-insulator as an enabling technology for future dense photonic integrated circuits. These waveguides are defined with 248nm deep UV lithography and have losses as low as 2.4dB/cm for a width of 500nm at 1550nm wavelength. Bends and directional couplers are fabricated and used to build ring resonators with 5μm radius, Q-factors higher than 3000 and insertion loss of around 2dB. The experimental results show clear agreement with a theoretical model of the resonators. We analyze the fabrication tolerances allowed for these resonators to be suitable as a building block for WDM filtering components.