Laser ablation analysis system

摘要

Systems, methods, compositions, and apparatus for laser induced ablation spectroscopy are disclosed. A sample site position sensor, stage position motors operable to move the stage in three independent spatial coordinate directions, and a stage position control circuit can move an analysis sample site to selected coordinate positions for laser ablation. Light emitted from a plasma plume produced with laser ablation can be gathered into a lightguide fiber bundle that is subdivided into branches. One branch can convey a first portion of the light to a broadband spectrometer operable to analyze a relatively wide spectral segment, and a different branch can convey a second portion of the light to a high dispersion spectrometer operable to measure minor concentrations and/or trace elements. Emissions from a plasma plume can be simultaneously analyzed in various ways using a plurality of spectrometers having distinct and/or complementary capabilities.

主权项

1. An apparatus for ablation spectroscopy, comprising:
a stage to support a sample, the stage being operable to move in x and y directions of a plane, and in a z (height) direction perpendicular to the plane during a process of laser ablation from different sites on the sample surface; an ablation source operable to ablate material from a first sample site on the surface into a first luminous plasma plume and to ablate material from a second sample site on the surface into a second luminous plume during the process; a position sensor operable to sense a difference in height of the first sample site relative to height of the second sample site and generate a displacement signal proportional to the difference in height, during the process; a stage position control circuit operable to automatically maintain an optimum height of the first and the second sample sites during the process based on the displacement signal; one or more fiber optic lightguides having at least one proximal end and a plurality of distal ends; at least one collection optics module operable to gather light emanating from the plasma plume into the proximal end of a fiber optic lightguide; a plurality of spectrometers, wherein each spectrometer includes wavelength separation means and a detector, and wherein each spectrometer is coupled to an associated distal end of a fiber optic lightguide; and a computer operable to receive wavelength and intensity values from each of the spectrometers, determine a representation of a sample composition based on the received wavelength and the intensity values, and output and/or record the representation and/or wavelength and intensity values;wherein
the ablation of the material from the first sample site is operable to change the height of the first sample site before the adjustment of the height of the stage and the ablation of material from the second sample site; and each of the spectrometers is operable to receive a portion of light from the plasma plume from the respectively associated distal fiber optic lightguide end, and all of the spectrometers are operable to receive the portions of the light simultaneously.