Patent ID: 8508592

Claim:
A spatially-selective reflective structure comprising: a partially-conducting slab; and a modulating reflector disk adjacent to the partially-conducting slab, the modulating reflector disk having one or more modulations; wherein: the distance between the modulations of the modulating reflector disk and the partially-conducting slab is defined by the formula d n = n ⁢ λ 2 ⁢ ɛ r ⁢ cos ⁡ ( ϕ i ) , n=1, 2, . . . ; or the distance between a non-modulated surface of the modulating reflector disk and the partially-conducting slab is defined by the formula d r = ( 2 ⁢ n - 1 ) ⁢ λ 4 ⁢ ɛ r ⁢ cos ⁡ ( ϕ i ) , n = 1 , 2 , … ⁢ ; and ε r is the relative permittivity of the media between the partially-conducting slab and the modulations, λ is the wavelength of interest, and φ i is the angle of radiation incidence given with respect to a normal of the spatially-selective reflective structure.