Advanced photonic filters based on cascaded Sagnac loop reflector resonators in silicon-on-insulator nanowires

Jiayang Wu, Tania Moein, Xingyuan Xu, David J. Moss

Research output: Contribution to journalArticleResearchpeer-review

41 Citations (Scopus)


We demonstrate advanced integrated photonic filters in silicon-on-insulator (SOI) nanowires implemented by cascaded Sagnac loop reflector (CSLR) resonators. We investigate mode splitting in these standing-wave (SW) resonators and demonstrate its use for engineering the spectral profile of on-chip photonic filters. By changing the reflectivity of the Sagnac loop reflectors (SLRs) and the phase shifts along the connecting waveguides, we tailor mode splitting in the CSLR resonators to achieve a wide range of filter shapes for diverse applications including enhanced light trapping, flat-top filtering, Q factor enhancement, and signal reshaping. We present the theoretical designs and compare the CSLR resonators with three, four, and eight SLRs fabricated in SOI. We achieve versatile filter shapes in the measured transmission spectra via diverse mode splitting that agree well with theory. This work confirms the effectiveness of using CSLR resonators as integrated multi-functional SW filters for flexible spectral engineering.

Original languageEnglish
Article number046102
Number of pages11
JournalAPL Photonics
Issue number4
Publication statusPublished - Apr 2018
Externally publishedYes

Cite this