Spatiotemporally resolved spectra of gaseous discharge between electrodes triggered by femtosecond laser filamentation

Atmospheric pressure discharge plasma is widely utilized in industry and science. However, due to the spatiotemporal uncertainty of the natural discharge, it is difficult to measure the discharge plasma spectra with a high spatiotemporal resolution. This prevents the accurate investigation of discharge plasma evolution and limits further applications. Here, we harnessed a femtosecond laser filament to trigger and guide a high-voltage discharge, i.e., the discharge plasma channel is rigorously controlled by the filament in both space and time. Therefore, the spectra of the plasma channel with a high spatiotemporal resolution could be measured using an imaging spectrometer. The spectra of the whole process of femtosecond laser filament-triggered discharge plasma are thoroughly studied. According to the spectral emission features, the whole process is divided into three stages: femtosecond laser filamentation, streamer propagation, and discharge. The spectral emissions at different stages can be utilized as required according to the spectral emission features. Based on the spatiotemporally resolved spectra of the streamer, the streamer propagation velocity is calculated to be about 3 x 10(5) m/s. In addition, atomic emissions from a discharge plasma triggered by femtosecond laser filament can be used for one-dimensional component measurements of flow fields.

Automated summary

In this study, the evolution of discharge plasma is investigated using a femtosecond laser filament to trigger and guide a high-voltage discharge. The spectra of the plasma channel with high spatiotemporal resolution are measured using an imaging spectrometer. The whole process is divided into three stages based on spectral emission features, and the streamer propagation velocity is calculated to be about 3 x 10(5) m/s. The atomic emissions from the discharge plasma triggered by the laser filament can be utilized for one-dimensional component measurements of flow fields.