Dynamic Mode Splitting and Plasma-Induced Transparency in Microplasma Photonic Crystals

Microplasma-based photonic crystals having a 3D structure, a lattice constant of 1 mm, and operating in the 110-170 GHz spectral region have been designed and realized at the University of Illinois. These 3D periodic structures allow for the integration of complex metallic structures with plasma microcolumns, thereby creating versatile platforms to study plasma-resonator interactions and active tuning of electromagnetic modes. By exploiting the frequency dependence of the dielectric permittivity of low temperature plasma, the strength of cavity-waveguide coupling can be tuned by the electron density.

 

Active tuning of the transmittance spectra and wave group velocities in the 110 – 170 GHz spectral interval have been observed and will be described. Dynamic mode splitting occurs at 131.8 GHz in transmittance spectra by plasma tuning through varying the magnitude of the voltage and pulse width. Plasma-induced electromagnetic transparency is also demonstrated by changing the time-averaged electron density through manipulating the voltage pulse width. These dynamic crystals provide functionality not available with conventional photonic crystals and yet are reconfigurable at electronic speeds.