Parallel-Output Flat-Top Microring Arrays for WDM Demultiplexer Applications

In this letter, novel microring arrays with flat-top outputs are proposed and experimentally demonstrated on an integrated silicon platform for WDM demultiplexer applications. Multiple microrings in series have parallel-output and can be detected by a single photodetector, representing one channel response of WDM. The measured results show that the proposed 8-channel demultiplexer with 1.5 nm channel spacing exhibits a −11.7 dB crosstalk with an increase in bandwidth from 0.44 nm for a single ring to 1.18 nm. Theoretical analysis suggests that using second-order microrings can further improve the crosstalk to −25 dB.