Laser-induced breakdown spectroscopy (LIBS) is attractive for fast, on-site, and remote
measurement of trace elements with high spatial resolution. The measurement of chlorine concentration
in concrete, which can be useful for the evaluation of durability of reinforced concrete structures, was
performed with a sensitivity of better than 0.18 kg/m3, which is below the threshold chlorine
concentration of 0.6 kg/m3 at which the reinforcing bars in concrete structures start to corrode. In
addition, ultrashort laser pulses have several advantages for application to LIBS. The propagation of an
ultrashort high-intensity laser pulse in the atmosphere produces a bundle of filaments, which can be
generated for a distance of more than several hundreds of meters and have sufficient intensity for
producing plasmas at various targets. LIBS using filaments, called filament-induced breakdown
spectroscopy (FIBS), is very useful for remote measurement of trace elements. Remote detection and
identification of microparticles in air by FIBS at a distance of 16 m was demonstrated. In addition, as a
new application of LIBS, remote measurement of the electric field is presented.
Keywords: Laser-induced breakdown spectroscopy, chlorine, concrete, filament, emission spectroscopy,
ultrashort pulse laser, plasma, saltwater aerosols, remote measurement, electric field.
