The high dependence of polarization resolved laser-induced breakdown spectroscopy on experimental conditions

It is shown that the continuum emission produced by the Al alloy ablated by femtosecond laser pulses is much more polarized than the characteristic lines of elements. A Glan--Thomson polarizer is used in the laser-induced breakdown spectroscopy experiment to investigate the polarization effect. The use of polarizer at its minimal transmission increases the signal-to-noise ratio. The effects of angle of detection, focal position, and pulse energy on the signal-to-noise ratio are also studied.