Microwave-Enhanced Laser-Induced Breakdown Spectroscopy

A new laser-induced air plasma source assisted by locally intensified microwave radiation was developed. A locally intensified microwave field was formed in a confined mesh chamber with an antenna to transfer microwave energy from the surroundings into the plasma source. A pulsed Nd-YAG laser was used to initiate breakdown and generate the plasma source. The microwave-enhanced plasma had a large volume and high intensity emission. In the plasma, electrons absorbed the microwave power, putting it out of thermal equilibrium. Molecular band spectra and metal atomic spectra were observed in the microwave-enhanced plasma source. 1