Metamaterial induced bound state in continuum via the self-complementary Babinet principle

Area of Science:

• Photonics
• Metamaterials
• Electromagnetics

Background:

• High-Q resonances are essential for photonic devices like sensors and lasers.
• Bound states in the continuum (BIC) offer a pathway to achieving these resonances.

Purpose of the Study:

• To comprehensively study BIC in complementary planar Babinet metamaterials.
• To demonstrate the induction of a symmetry-protected BIC for high-Q factor resonances.

Main Methods:

• Investigated BIC in planar metamaterials operating in the microwave regime.
• Utilized wave rotation from normal incidence to induce a symmetry-protected BIC.

Main Results:

• Achieved a high Q-factor of 9.245 × 10³ (theoretical) and 1.606 × 10³ (experimental).
• Localized trapped modes at 6.625 GHz with electric dipole and octopole components.
• Radiation was confined exclusively within the metamaterial plane.

Conclusions:

• Demonstrated a viable method for inducing symmetry-protected BIC in planar metamaterials.
• The findings show potential for developing novel planar lasers and other photonic devices.