The LIBS microscope has the capacity to provide fast elemental mapping of flat surfaces, typically cross-sections of geological samples, marine shells [1], bones, teeth etc. [2] The 2D-elemental maps of the scanned surface can be used to identify the distribution of mineral phases in rocks, to measure the variability of elemental proxies related to paleoenvironment in shell studies or to assess the diffusion of environmental pollutants into hard tissues. 

In the present micro-LIBS workstation [3] [3]a Q-switched Nd:YAG laser is used (λ = 1064 nm, pulse duration: 10 ns, pulse energy 5-20 mJ). The laser beam is focused on the sample through a laser objective lens down to a spot of 40 - 60 μm in diameter. The light emitted by the plasma is transferred via an optical fiber to the spectrometer which captures LIBS spectra for each one of the laser pulses that scans the surface. According to specific analysis requirements the spectral data is processed on-line or following completion of scanning. Samples are mounted on a motorized X–Y–Z micrometric stage and translated with respect to the laser beam that remains in a fixed position. The typical translation step is of the order of 100 μm. A CCD camera enables the user to have a clear view of the sample surface and to define the area that is to be mapped (any shape is acceptable). The measurement speed is about 0.9 s per point and each map could have 500 - 6000 points (i.e. an elemental map of 4000 points is obtained in about 1 hr). A dual spectrometer unit (AvaSpec-2048-2-USB2) records the LIBS signal (spectral range: 200 - 640 nm, resolution ~ 0.2 - 0.3 nm). For higher sensitivity, the signal can be recorded by a Czerny-Turner spectrometer (Jobin Yvon, TRIAX 320) with an ICCD camera (DH734–18F, Andor Technology) (spectral range ~ 45 nm).