AUTHOR=Chen Jianfeng , Qin Qiumeng , Peng Chaoqun , Liang Wenyao , Li Zhi-Yuan 

TITLE=Slow Light Rainbow Trapping in a Uniformly Magnetized Gyromagnetic Photonic Crystal Waveguide

JOURNAL=Frontiers in Materials

VOLUME=Volume 8 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2021.728991

DOI=10.3389/fmats.2021.728991

ISSN=2296-8016

ABSTRACT=We present a hybrid gyromagnetic photonic crystal (GPC) waveguide composed of different GPC waveguide segments possessing various cylinder radii and waveguide widths but biased by a uniform external magnetic field. We demonstrate in frequency and time domains that based on the strongly coupling of two counter-propagating topologically protected one-way edge states, the intriguing slow light rainbow trapping (SLRT) of electromagnetic (EM) waves can be achieved, i.e. EM wave of different frequencies can be slowed down and trapped at different positions without crosstalk and overlap. More importantly, due to the existence of one-way edge states, external EM waves can be nonreciprocally and high-efficiently coupled into the SLRT waveguide channel although the incident position of the EM wave is far away from the waveguide channel. Besides, the frequency range of the slow light states can also be easily regulated by tuning the intensity of external magnetic field, which is very beneficial to solve the contradiction between slow light and broad bandwidth. Our results can be applied to the design of high-performance photonic devices, such as optical buffer, optical switch and optical filter.