Beam Deflection with Unidirectionality due to Zeroth Order and Evanescent Wave Coupling in a Photonic Crystal With a Defect Layer Without Corrugations Under Oblique Incidence

Single beam deflection and unidirectionality are observed in a photonic crystal (PC) without surface corrugations, employing a defect layer. These effects are seen even when defect layer is deeply buried. Two types of... [ view full abstract ]

Single beam deflection and unidirectionality are observed in a photonic crystal (PC) without surface corrugations, employing a defect layer. These effects are seen even when defect layer is deeply buried. Two types of deflection is observed. In the first, Floquet-Bloch modes enable zeroth order coupling. When zeroth order is blocked, diffractions cause blazing and evanescent waves deliver energy to higher order diffraction modes. Without surface corrugations transmission value T≈0.97 is achieved due to diffraction order m=-1. Utilizing an extra line defect, T increases upto 0.99, even if the line defect layer is deeply embedded in PC.