Interchannel optical coupling within arrays of linear microplasmas generated in 25–200μm wide glass channels

摘要

Axially uniform microcavity plasmas with widths of 25–200 μm and aspect ratios as high as 500 have been generated in glass microchannels. Sealed in cavities 2.5 cm in length and having a cross-sectional area of 2.5×102–104 μm2, these microplasmas operate in the abnormal glow regime with neutral particle temperatures of 365–420 K when the rare gas pressure is 200–700 Torr. In arrays as large as ten parallel microchannel plasmas, evidence of optical coupling among the channels is observed in the form of strongly enhanced atomic emission which is attributed to electron heating driven by the resonant absorption of scattered radiation.