Plasma-grating-induced breakdown spectroscopy

Abstract

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.

Femtosecond laser-induced breakdown spectroscopy by multidimensional plasma grating

“…Moreover, as the direct result of the wavelength-scale periodic structures of the plasma gratings, the interacting laments induced micro-structured ablation in the samples, facilitating nearly homogeneous breakdown on irregular sample surfaces to overcome the matrix effects. 35,38,39 On the other hand, electron densities were enhanced in the established plasma gratings, and impact ionization occurred in the plasma waveguide, as demonstrated in previous experiments. 31 This might bring about additional impact excitations upon plasma ablation, leading to promising enhancement of breakdown spectroscopy in comparison with the standard LIBS or FIBS.…”

“…31 This might bring about additional impact excitations upon plasma ablation, leading to promising enhancement of breakdown spectroscopy in comparison with the standard LIBS or FIBS. 35…”

“…31 This might bring about additional impact excitations upon plasma ablation, leading to promising enhancement of breakdown spectroscopy in comparison with the standard LIBS or FIBS. 35 In addition, the inter-pulse delay of a few hundred femtoseconds could bring about drastic changes in the femtosecond lament interaction, resulting in an observable decrease of spectral line signals induced by MIBS. For this experimental conrmation, we studied the effect of the inter-pulse delay on the spectral line signal.…”

“…Fortunately, the plasma grating generated by the strong interaction of femtosecond laments [25][26][27][28][29][30][31] can effectively break through the clamping intensity limit, which has already been used for quasi-phase matched third harmonic generation (THG), 32 signicant THG enhancement, 33 and noticeable energy transfer from one lament to the other. 34 Hu et al 35 innovatively introduced a plasma grating into LIBS to form plasma-gratinginduced breakdown spectroscopy (GIBS) to analyze soil samples and successfully obtained a stronger spectral signal and better detection performance. In such a technique, two non-collinear optical laments interact to form one-dimensional (1D) plasma gratings, and plasma gratings rather than single laments were used to ablate the sample.…”

Atomic spectrometry update: review of advances in atomic spectrometry and related techniques

“…Interference of two noncolinear fs filaments was employed by Hu et al 131 to generate a plasma grating, which was able to provide a higher local electron density. The authors observed that the resultant plasma grating induced breakdown spectroscopy system resulted in enhanced atomic emission signals compared to single filament induced breakdown spectroscopy, with reduced matrix effects.…”