Comparing Q-factor of electromagnetically induced transparency based on different space distribution quasi-dark mode resonator

Comparing the Q-factor of electromagnetically induced transparency based on a symmetric and asymmetric quasi-dark resonator has been numerically and experimentally demonstrated. The results show that the Q-factor of electromagnetically induced transparency based on the symmetric quasi-dark mode resonator is an order of magnitude larger than that based on the asymmetric quasi-dark mode resonator. The reason for the improved Q-factor is ascribed to the low radiative loss of the symmetric quasi-dark mode resonator. Furthermore, the proposed way holds promise to obtain a different Q-factor of electromagnetically induced transparency in the microwave, terahertz, and optical frequency range.