Broadband tuning of plasma photonic crystal bandgaps using pixilated plasma distributions within a supercell

Abstract

Plasma photonic crystals (PPCs) are photonic crystals formed from plasma that allows them an electrically tunable structure and permittivity. PPCs are potential microwave bandgap components with frequency ranges theoretically limited only by the physical control of the plasma distribution. In practice, they are limited by the controllability of the plasma distribution. Traditional approaches have minimal control and range of PPC reconfigurability because the plasma distribution is fixed. In contrast, this work explores reconfiguring the PPC structure by treating individual columns as pixels within a larger PPC structure. While the location of each plasma column is fixed, individual columns are adjusted to change the macroscopic plasma distribution of the total PPC. This work shows for the first time that individual plasma column control can tune a PPC bandgap frequency by an order of magnitude, from 190–300 GHz to 26–37 GHz. The changes to the larger supercell structure emulate changes to PPC parameters such as the lattice constant, column radius, and permittivity. This enables a wider tunable frequency range for PPC bandgaps as well as improved manipulation over the range. The collision frequency imposes a lower limit on the variable frequency range. The results demonstrate an expanded frequency variability for PPCs that highlight their potential as a wideband tunable bandgap device when each column is individually controlled.