Generation and confinement of microwave gas-plasma in photonic dielectric microstructure

We report on a self-guided microwave surface-wave induced generation of similar to 60 mu m diameter and 6 cm-long column of argon-plasma confined in the core of a hollow-core photonic crystal fiber. At gas pressure of 1 mbar, the micro-confined plasma exhibits a stable transverse profile with a maximum gas-temperature as high as 1300 +/- 200 K, and a wall-temperature as low as 500 K, and an electron density level of 10(14) cm(-3). The fiber guided fluorescence emission presents strong Ar+ spectral lines in the visible and near UV. Theory shows that the observed combination of relatively low wall-temperature and high ionisation rate in this strongly confined configuration is due to an unprecedentedly wide electrostatic space-charge field and the subsequent ion acceleration dominance in the plasma-to-gas power transfer. (C) 2013 Optical Society of America