Novel optical media with adjustable spectra and polarization based on the magnetized plasma dipole oscillation

Since the discovery of plasma dipole oscillation, it has been used in a variety of applications, including ultra-high power Terahertz sources and plasma diagnostic methods. The new technique for producing terahertz emission using a plasma dipole oscillation (PDO) results in considerably narrower band, spectrum-controllable radiation. Previous researches have revealed energy conversion efficiency can be beyond 10 and has proposed innovative diagnostics methods. Recently we found that response of PDO to the external magnetic field is interesting and beneficial as an optical component. PDO is implemented by colliding detuned electromagnetic (EM) waves (typically laser pulses) to emit linearly polarized THz radiation at the plasma frequency in a radial direction. Magnetized PDO, on the other hand, shows much richer radiation characteristics as it emits in both transverse and longitudinal polarization at diversely different frequencies. These characteristics originate from the PDO dynamics under the magnetized plasma. The magnetized PDO consists of three modes: right circular (R), left circular (L), and upper hybrid modes. Each electron of PDO circulates either right-handed or left-handed. The right circular and left circular modes come out as results of single electron motion under the external magnetic field. However, upper hybrid mode is formed from the average motion. The upper hybrid mode works for sustaining the coherency of PDO.