All-dielectric antislot waveguide with subwavelength mode confinement and its high-efficiency coupling with input/output fiber

Due to metallic ohmic loss, plasmonic waveguides usually have larger propagation loss. Here, an alldielectric antislot waveguide was proposed, which can realize subwavelength mode confinement and theoretically lossless propagation simultaneously. A normalized mode area of 3.4x10(2) was achieved in the all-dielectric antislot waveguide. Moreover, an efficient coupling scheme between the small-size antislot waveguide and input/output fiber was proposed. An overall coupling efficiency of 92. 7% was attained. The misalignment tolerance for 1 dB loss penalty was about 2 mu m in both y and z directions.