Radiation of a Charge Exiting Open-Ended Waveguide with Dielectric Filling

Abstract

We consider a semi-infinite open-ended cylindrical waveguide with uniform dielectric filling placed into collinear infinite vacuum waveguide with larger radius. Electromagnetic field produced by a point charge or Gaussian bunch moving along structure's axis from the dielectric waveguide into the vacuum one is investigated. We utilize the modified residue-calculus technique and obtain rigorous analytical solution of the problem by determining coefficients of mode excitation in each subarea of the structure. Numerical simulations in CST Particle Studio are also performed and an excellent agreement between analytical and simulated results is shown. The main attention is paid to analysis of Cherenkov radiation generated in the inner dielectric waveguide and penetrated into vacuum regions of the outer waveguide. The discussed structure can be used for generation of Terahertz radiation by modulated bunches (bunch trains) by means of high-order Cherenkov modes. In this case, numerical simulations becomes difficult while the developed analytical technique allows for efficient calculation of the radiation characteristics.

13 pages, 11 figures

References in corpus (2)

• Self-starting harmonic frequency comb generation in a quantum cascade laser
• Coupling Impedances of Small Discontinuities: Dependence on Beam Velocity

Cited by in corpus (5)

• Cherenkov radiation and emission of surface polaritons from charges moving paraxially outside a dielectric cylindrical waveguide
• Self-amplification of radiation from an electron bunch inside a waveguide filled with periodic medium
• Diffraction at the Open End of Dielectric-Lined Circular Waveguide
• Diffraction at the Open-Ended Dielectric-Loaded Circular Waveguide: Rigorous Approach
• Quasidiscrete spectrum Cherenkov radiation by a charge moving inside a dielectric waveguide