Precise control of the discharge in space and time is of great significance for better applications of discharge plasma.Here,we used a femtosecond laser filament to trigger and guide a highvoltage DC pulse discharge t...Precise control of the discharge in space and time is of great significance for better applications of discharge plasma.Here,we used a femtosecond laser filament to trigger and guide a highvoltage DC pulse discharge to achieve spatiotemporal control of the discharge plasma.In space,the discharge plasma is distributed strictly along the channel generated by the femtosecond laser filament.The breakdown voltage threshold is reduced,and the discharge length is extended.In time,the electrical parameters such as the electrode voltage and the electrode gap affect discharge delay time and jitter.By optimizing the parameters,we can achieve sub-nanosecond jitter of the discharge.Based on the spatiotemporal control of the discharge,we applied filamenttriggered discharge for one-dimensional composition measurements of the gas flow field.Besides,the technique shows great potential in studying the spatiotemporal evolution of discharge plasma.展开更多
.Laser-induced breakdown spectroscopy(LIBS)is a useful tool for determination of elements in solids,liquids,and gases.For nanosecond LIBS(ns-LIBS),the plasma shielding effect limits its reproducibility,repeatability,a....Laser-induced breakdown spectroscopy(LIBS)is a useful tool for determination of elements in solids,liquids,and gases.For nanosecond LIBS(ns-LIBS),the plasma shielding effect limits its reproducibility,repeatability,and signal-to-noise ratios.Although femtosecond laser filament induced breakdown spectroscopy(FIBS)has no plasma shielding effects,the power density clamping inside the filaments limits the measurement sensitivity.We propose and demonstrate plasma-grating-induced breakdown spectroscopy(GIBS).The technique relies on a plasma excitation source-a plasma grating generated by the interference of two noncollinear femtosecond filaments.We demonstrate that GIBS can overcome the limitations of standard techniques such as ns-LIBS and FIBS.Signal intensity enhancement with GIBS is observed to be greater than 3 times that of FIBS.The matrix effect is also significantly reduced with GIBS,by virtue of the high power and electron density of the plasma grating,demonstrating great potential for analyzing samples with complex matrix.展开更多
基金funded by National Natural Science Foundation of China(NSFC)(Nos.51806149,91741205)。
文摘Precise control of the discharge in space and time is of great significance for better applications of discharge plasma.Here,we used a femtosecond laser filament to trigger and guide a highvoltage DC pulse discharge to achieve spatiotemporal control of the discharge plasma.In space,the discharge plasma is distributed strictly along the channel generated by the femtosecond laser filament.The breakdown voltage threshold is reduced,and the discharge length is extended.In time,the electrical parameters such as the electrode voltage and the electrode gap affect discharge delay time and jitter.By optimizing the parameters,we can achieve sub-nanosecond jitter of the discharge.Based on the spatiotemporal control of the discharge,we applied filamenttriggered discharge for one-dimensional composition measurements of the gas flow field.Besides,the technique shows great potential in studying the spatiotemporal evolution of discharge plasma.
基金We acknowledge the support fromthe National Key Research and Development Program(No.2018YFB0407100)the National Natural Science Foundation of China(No.11621404)the Key Project of Shanghai Education Commission(No.2017-01-07-00-05-E00021).
文摘.Laser-induced breakdown spectroscopy(LIBS)is a useful tool for determination of elements in solids,liquids,and gases.For nanosecond LIBS(ns-LIBS),the plasma shielding effect limits its reproducibility,repeatability,and signal-to-noise ratios.Although femtosecond laser filament induced breakdown spectroscopy(FIBS)has no plasma shielding effects,the power density clamping inside the filaments limits the measurement sensitivity.We propose and demonstrate plasma-grating-induced breakdown spectroscopy(GIBS).The technique relies on a plasma excitation source-a plasma grating generated by the interference of two noncollinear femtosecond filaments.We demonstrate that GIBS can overcome the limitations of standard techniques such as ns-LIBS and FIBS.Signal intensity enhancement with GIBS is observed to be greater than 3 times that of FIBS.The matrix effect is also significantly reduced with GIBS,by virtue of the high power and electron density of the plasma grating,demonstrating great potential for analyzing samples with complex matrix.
