Superscattering-enhanced narrow band forward scattering antenna
Hu De-Jiaoa),b),c), Zhang Zhi-Youa),b),c), Du Jing-Lei†a),b),c)
       
(a) Forward ( σ f, black dashed) and backward ( σ b, red dash dotted) scattering cross section of the CAA with r 1 = 70 nm, r 2 = 140 nm, and r 3 = 190 nm ( t = 50 nm). The blue dotted line represents the integral of the square of the modulus of the electric field over the dielectric layer, which is proportional to the stored energy. The electric field distributions within the CCA are displayed under their corresponding peaks as insets. (b) The variations of ratio between forward and backward scattering cross section ( σ f/ σ b) with wavelength for t = 30 nm, 40 nm, and 50 nm respectively. (c) Radiation patterns (power to the far field) for off-resonance position (green dotted line) at t = 50 nm and ratio ( σ f/ σ b) peak positions (blue solid and red dashed for t = 50 nm, black dash–dotted for t = 30 nm). (d) The map of the ratio between forward scattering and back scattering against the thickness of the cladding and wavelength.