Low-loss and high index-contrast tantalum pentoxide microring resonators and grating couplers on silicon substrates

A platform for high index-contrast integrated photonics based on tantalum pentoxide submicrometer waveguides on silicon substrates is introduced. The platform allows demonstration of microring resonators with loaded quality factor, Q, of 67,000 and waveguides with a propagation loss of 4.9 dB/cm. Grating couplers, with an insertion loss of similar to 6 dB per coupler and 3 dB bandwidth of similar to 50 nm, are also demonstrated and integrated with microring resonators. (C) 2014 Optical Society of America