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The on-site detection of the geometrical topography and composition distribution of unknown minerals is a key bottleneck in the field of deep space exploration and geological material analysis. A novel portable confocal-controlled laser-induced breakdown spectroscopy (PCCLIBS) scanning three-dimensional (3D) imaging method with high spatial resolution and highly integrated structure was proposed to solve this problem. The method utilizes a confocal-controlled LIBS technique to achieve precise focusing of the sample, significantly improving the spatial resolution of the LIBS mapping system. In addition, we employ a dual two-dimensional (2D) MEMS mirror scanning technique to achieve a miniaturized design of LIBS mapping system. These two technologies are combined to achieve miniaturization, high spatial resolution, and 3D LIBS microelement imaging. The method had an axial focusing ability of ∼ 60 nm and a lateral resolution of geometrical and elemental maps of around 700 nm and 10 μm, respectively, using an objective lens with a numerical aperture (NA) of 0.4. Finally, we performed the LIBS and topographic imaging of carbonaceous chondrite (Northwest Africa 13323) using the PCCLIBS system to realize multi-information of the micro-regional chemical, element, and topographic information imaging in the sample. These results demonstrate that this method is an effective approach for the elemental characterization of LIBS in samples with complex morphologies, such as in planet landing exploration and geological exploration. [Display omitted] • A dual 2D MEMS mirror scanning method was proposed and applied to the confocal-controlled LIBS microscope. • Provided a new portable design method for spatially resolved LIBS imaging system, the main part of the optical path has a dimension of 168 mm × 50 mm. • The method achieved simultaneous rapid topographic and LIBS mapping with a high transverse resolution of ∼10.0 μm, and a high axial resolution of ∼11.5 μm. • The method is suitable for component analysis of extraterrestrial samples. [ABSTRACT FROM AUTHOR]

• Reduces the scanning time and data storage space of 3D topographic imaging. • Measuring height is unaffected by the sample reflectivity. • A novel alternative approach with higher lateral resolution level as conventional method. • Applied directly to existing confocal microscopy. Confocal microscopy (CM) is extensively used in many fields due to its unique axial tomographic capabilities and high-resolution three-dimensional imaging properties. However, this requires layer-by-layer scanning on the sample along the axial direction, which restricts the imaging speed. In this study, we have proposed the defocused differential correlation confocal microscopy (DDCCM), which is based on axial sensing imaging and correlation product method. This method can obtain an axial response curve independent of sample reflectivity and fast 3D sensing imaging of the sample by dividing the difference between the two defocused intensity images by their sum, improving the imaging efficiency at least five times higher than that of CM. The proposed method improves the lateral resolution using the correlation product of two defocused intensity images. DDCCM provides a new way for the fast measurement of conventional CM without changing the system conditions. [ABSTRACT FROM AUTHOR]

Laser induced breakdown spectroscopy (LIBS) is a promising analytical technique based on the interaction between laser and material, which can quantitatively analyse the composition and content of material from the perspective of spectroscopy. The element distribution of non-uniform samples, such as natural ore, can be obtained by pointwise scanning without pretreatment. LIBS excitation intensity is the highest near the focus, so low imaging speed and low focusing accuracy will lead to unreliable element maps. Hence, an ultrasensitive technique called unilateral-shift-subtracting confocal controlled LIBS microscopy (UCCLIBS) was prepared to rapidly acquire high spatial resolution multi-elemental maps of the sample surface, which utilizes a laser induced breakdown spectrometer attached to a unilateral-shift-subtracting confocal microscope. A surface axial focusing ability of approximately 18 nm under 20× objective lens with the N.A. value of 0.4 is obtained, which is more than two orders of magnitude higher than that of ever traditional LIBS approaches, and the inherent anti-drift capability is successfully realized. The chemometric method of principal component analysis (PCA) is applied to the multi-element analysis of agate ore, which improved the accuracy and efficiency of sample analysis. We show the multi-layer element map of a solid-state electrolyte with a tomographic resolution of 2.3 μm. With these excellent properties, the UCCLIBS might provide a new idea for the detection of three-dimensional elemental characterization of minerals and chemical materials. We present a novel technique termed unilateral-shift-subtracting confocal laser-induced breakdown microscopy (UCLIBS), which utilizes a laser induced breakdown spectrometer attached to a unilateral-shift-subtracting confocal microscope to rapidly acquire high spatial resolution multi-elemental maps of the sample surface. This technique shows a surface axial focusing ability of approximately 18 nm under 20× objective lens with the N.A. value of 0.4, which is more than two orders of magnitude higher than that the traditional LIBS approaches, and provides inherent anti-drift capability. The chemometric method of principal component analysis (PCA) is applied to the multi element analysis of agate ore, which improved the accuracy and efficiency of sample analysis. We show the multi-layer element map of a solid-state electrolyte with a tomographic resolution of 2.3 μm. The experimental results demonstrate that the UCLIBS can be extended to the three-dimensional elemental characterization of minerals and chemical materials. [Display omitted] • The system has a high spatial resolution and can be realized Multi-layer elemental maps for the solid-state electrolyte with a depth resolution of 2.3 μm. • This technique shows a high axial focusing ability of approximately 18 nm, which is more than two orders of magnitude higher than that the traditional LIBS approaches. • UCLIBS system has a transverse resolution of 600 nm, and its imaging stability is better than the traditional LIBS system. [ABSTRACT FROM AUTHOR]