Development of a large depth of field collection optics for on-line Laser-Induced Breakdown Spectroscopy applications

Spectral stability improvement through wide fields of view collection optics in laser-induced breakdown spectroscopy applications

“…The spectral signal is obtained by integrating the plasma emission within the time and spatial window of the collection system. [14][15][16][17][18] The time window, including delay time and gate width, is usually optimized in LIBS experiments to avoid high continuous background radiation from plasma emission at the early stage and to maximize signal-to-noise ratios. In a typical LIBS analysis, the plasma exhibits a plume shape with dimensions reaching several millimetres and spatial electron temperature and density inhomogeneities.…”

“…27 The collecting geometry is determined by the conguration of the collection optics, which can be dened by the axial depth of eld and vertical eld of view of the collection efficiency distribution. 16,17 The depth of eld of the collection optics is usually sufficient to cover the entire plasma, 25 but the eld of view is relatively small, limiting the emission collection to a small region of the plasma. 17,27,28 The eld of view is an important parameter for optimizing spectra in a general LIBS analysis.…”

Evaluation of femtosecond laser-induced breakdown spectroscopy system as an offline coal analyzer

“…Coal properties; ash content, volatile matter content, and calorific value, were predicted using SVM combined with PCA and the average relative error of prediction reduced from 8.3% to 5.48%, 5.83% to 4.42%, and 5.4% to 3.68%, respectively. On a laboratory level, Redoglio et al 7 , 8 designed a moving system comprised a 500 mm-diameter circular array to house coal samples and rotate at fixed speed. The optical system with a large depth-of-field mirror was utilized to overcome the changing in coal rocks’ height.…”