A Novel Device for Generating Terahertz Radiation Pulses
  The dynamics of a core-shell structured ionized particle between two parallel conductor plates, which is biased with a direct current (DC) voltage, have been investigated. It has been found that an ionized particle oscillates rapidly between the DC voltage biased parallel conductors, where the frequency of oscillation depends on the free-charge density carried by the particle, the DC bias voltage, and the gap across the two conductor plates. As the presented system involves a spatially oscillating ionized particle, it represents a natural prototype for the electric dipole radiation source. Since the frequency of oscillating ionized particle depends on the DC bias voltage across the parallel conductor plates, the presented device has a broad wavelength adjustment range for the emitted radiation. 
Sung Nae Cho
physics.class-ph