Coupling of free space sub-terahertz waves into dielectric slabs using PC waveguides

Abstract

The paper presents theoretical and experimental results on photonic crystal structures which work under the self-collimation condition to couple free space waves into dielectric slabs in the sub-terahertz range. Using a standard machining process, two-dimensional photonic crystal structures consisting of a square array of air holes in the dielectric medium are fabricated. One of the structures has two adjacent parallel line-defects that improve the coupling efficiency. This leads to a combination of self-collimation and directional emission of electromagnetic waves. The experimental results are in good agreement with those of the Finite- Element-Method calculations. Experimentally we achieve a coupling efficiency of 63%.

Optical interconnections with photonic crystal self-collimation, directional emission and co-directional coupling mechanism

“…On the other hand, for a dispersion-based self-collimation [8,9] structure, light can be confined without considerable broadening and changing in the beam profile in twodimensional (2D) PCs. Very recently, theoretical [10,11] and experimental [12] investigations have been made on the highly efficient directional emission behaviour via the selfcollimation effect. In [10] a combination of self-collimation and directional emission was suggested to realize the coupling of free space terahertz waves into a silicon slab.…”

“…In [11] the authors adopted the advantage of the directional coupling mechanism to propose a new kind of beam splitter. In [12] 2D PC structures consisting of a square array of air holes in a dielectric medium were fabricated. One of the structures had two adjacent parallel line-defects to improve the coupling efficiency that led to a combination of self-collimation and directional emission of electromagnetic waves.…”