DOI: 10.1109/TMTT.2025.3599502   IEEEXplore: https://ieeexplore.ieee.org/document/11142831

Silicon photonic (SiP) bend-coupled microdisk resonator (MDR) with an ultrahigh Q-factor

1558.36 nm

A bend bus waveguide is engineered to satisfy the strict phase-matching condition for the fundamental whispering gallery mode (WGM) while selectively suppressing the higher order WGMs by fabricating a bend bus waveguide radius 30% larger (52 µm) than the disk radius (40 µm). This optimized coupling enables an ultra-high-Q resonance with a 0.46 pm bandwidth, surpassing the performance of conventional straight-coupled designs (1.14 pm) by more than 60%. Our approach provides a compact and robust solution for high-performance microwave photonic applications.

5G and 6G wireless networks, next-gen electronic warfare and cognitive radio applications demanding widely tunable ultrahigh Q filtering.

MDR with an ultrahigh Q-factor of 3.3 x 106 and a large free spectral range of 2.67 nm; Microwave photonic filter with a narrow passband of 59 MHz and a wide tuning range of 50 GHz ; Photonics-assisted frequency identification system with a measurement range of 6-46 GHz, a high frequency resolution of 80 MHz and a high measurement accuracy of 14.5 MHz.