Obtaining photonic jet by the rectangular waveguid

A near-field concentration of an electromagnetic beam with a very small divergence on some propagation wavelength called "photonic jet" can be obtained by a dielectric sphere (Soon-Cheol Kong, 2010), a bi-plate guide (Takakura, 2014), a cylindrical guide (Gu, 2015), the optical fiber ( Photonic jet-shaped, 2021), the conical guide (Chittaranjan Nayak, 2016) or even a cubic structure (Cheng-Yang Liu, 2015). In this paper, we present a new fully guided structure that allows to obtain the photonic jet in order to replace the device based on free space excitation with more efficiency and easier handling. The outcome of our study show that a WR430 rectangular waveguide adapted by a pyramidal transition (Air-Teflon) and specified by a rectangular cross-section extension, generates photonic jets in the near field based on the Finite Element Method (FEM).