Fluorescence measurement and acoustic diagnostics of plasma channels in air
空气中激光等离子体通道的荧光探测和声学诊断两种方法的比较实验研究

A plasma channel up to 80 Rayleigh lengths is formed when intense femtosecond laser pulses propagate in air. Two methods, fluorescence measurement and acoustic diagnostics, are used to probe the plasma channel simultaneously. Both methods reveal the evolution of the channel in detail. Compared with the fluorescence measurement, the acoustic method is a convenient approach having higher sensitivity and higher spatial resolution in detecting long plasma channels.