“…In concert with the advance of complementary metal-oxide-semiconductor (CMOS) fabrication technologies, particularly as applied to photonic integrated circuits, integrated photonic resonators have become key building blocks [1,2]. With narrowband wavelength selectivity, strong resonance eld enhancement, and versatile lter shapes, these micro/nano-scale devices have been widely used for diverse applications including lters, lasers, modulators, buffers, switches, sensors, and signal processors [2][3][4][5][6][7][8][9][10]. and have also been applied to phase-sensitive all-pass lters [11][12][13][14][15].…”