Goldberg Benjamin M, Reuter Stephan, Dogariu Arthur, Miles Richard B
Opt Lett. 2019 Aug 1;44(15):3853-3856. doi: 10.1364/OL.44.003853.
We present an approach for the measurement of time evolving electric field profiles in atmospheric pressure plasma discharges using electric field induced second harmonic generation (E-FISH). While the E-FISH effect has been known of for some time, recent advances in laser and detection technology have allowed the method to be utilized for spatial measurements of an arbitrarily applied electric field. A cylindrical lens is used to focus the femtosecond laser light to a line and an intensified charge coupled device is used for detection, allowing for one-dimensional (1D) spatial resolution on the order of ∼50 μm. Measurements have been carried out verifying the spatial resolution using a spatially periodic, localized electric field. Calibrated 1D electric field measurements have been completed with a time resolution of 500 ps in a laminar cold atmospheric pressure plasma jet with argon core flow and N co-flow powered by a nanosecond (ns) pulse dielectric barrier discharge. The field was shown to propagate as an ionization wave, with a velocity of ∼0.3 mm/ns.
我们提出了一种利用电场诱导二次谐波产生（E-FISH）来测量大气压等离子体放电中随时间变化的电场分布的方法。虽然E-FISH效应已为人所知一段时间，但激光和检测技术的最新进展使得该方法能够用于对任意施加电场的空间测量。使用柱面透镜将飞秒激光聚焦成一条线，并使用增强型电荷耦合器件进行检测，从而实现约50μm量级的一维（1D）空间分辨率。已通过使用空间周期性的局部电场进行测量来验证空间分辨率。在由纳秒（ns）脉冲介质阻挡放电驱动的具有氩气中心流和氮气共流的层流冷大气压等离子体射流中，以500 ps的时间分辨率完成了校准的1D电场测量结果。结果表明，该电场以电离波的形式传播，速度约为0.3 mm/ns。
