Realization of a Chiral Topological Whispering‐Gallery‐Mode Cavity in Gyromagnetic Photonic Crystals
Year: 2024
Type: article
Abstract: Photonic whispering‐gallery‐mode (WGM) cavities formed by total internal reflection of light around closed paths have played a central role in modern optics. Recently, extensive efforts have been devoted to achieving topologically photonic WGM cavities that are robust against defects or obstacles. However, previous experimental studies on topological photonic WGM cavities are limited to systems with time‐reversal symmetry (TRS) and weak topological protection due to the existence of backscattering channels. Here, the study reports the experimental realization of a chiral topological WGM cavity in a gyromagnetic photonic crystal with broken TRS. Using microwave near‐field measurements, it is directly observed that the chiral topological WGM cavities are inherently nonreciprocal and exhibit superior robustness against various obstacles with strong topological protection owing to the absence of backscattering channels. More interestingly, it is demonstrated that the resonance frequencies and free spectral range (FSR) of the chiral topological WGM cavities can be tailored by adjusting the insertion length of a metallic scatterer. The work extends the research realm of topological photonic WGM cavities and may find important applications in designing arbitrary‐shaped and nonreciprocal topological photonic cavities, filters, lasers, and frequency combs.
Source: Laser & Photonics Review
Authors: Zhengting Wu, Ziyao Wang, Yan Meng, Jingming Chen, Xiang Xi, Perry Ping Shum, Zhen Gao
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funders: Innovative Research Group Project of the National Natural Science Foundation of China, National Natural Science Foundation of China, Science, Technology and Innovation Commission of Shenzhen Municipality, Young Elite Scientists Sponsorship Program by Tianjin, Basic and Applied Basic Research Foundation of Guangdong Province
Awards: G1368645004, G1383350147, G1430043668, G1604303627, G2200005471, G2268302589, G2408247463, G2408448451, G3114819178, G3359346188, G3566776132, G3620861224, G4078701312, G4350858411, G4788400864, G5338591164, G6023304815, G6831995549, G6835612449, G7324737297, G7511008168, G7557618666, G7647777557, G8761281093
OpenAlex ID: W4405536219