Analyzer alignment, sample detection, localization, and focusing method and system

Abstract

An analysis (e.g., LIBS) system includes a source of radiation, an optical emission path for the radiation from the source of radiation to a sample, and an optical detection path for photons emitted by the sample. A detector fiber bundle transmits photons to the spectrometer subsystem. At least one fiber of the fiber bundle is connected to an illumination source (e.g., an LED) for directing light via at least a portion of the detection path in a reverse direction to the sample for aligning, sample presence detection, localizing, and/or focusing based on analysis of the resulting illumination spot on the sample.

What is claimed is: 
     
         1 . An analysis system comprising:
 a source of radiation;   an optical emission path for the radiation from the source of radiation to a sample;   an optical detection path for photons emitted by the sample;   a spectrometer subsystem for analyzing said photons to determine sample elements and their concentrations and/or compounds present in the sample;   a detector fiber bundle for transmitting said photons to the spectrometer subsystem; and   at least one fiber of the fiber bundle connected to an illumination source, separate from the source of radiation for directing light, via at least a portion of the detection path, to the sample for aligning, sample presence detection, localizing, and/or focusing based on analysis of the resulting illumination spot on the sample.   
     
     
         2 . The system of  claim 1  in which the source of radiation is a laser, the optical emission path includes an apertured mirror and a focusing lens, and the detection path includes said focusing lens and the apertured mirror. 
     
     
         3 . The system of  claim 1  further including a camera aimed at the sample for viewing an illumination spot on the sample. 
     
     
         4 . The system of  claim 1  including means for aligning the fiber bundle by adjusting the position of the detection fiber bundle based on the illumination spot. 
     
     
         5 . The system of  claim 4  in which the means for aligning includes an adjustable fiber bundle mount. 
     
     
         6 . The system of  claim 5  in which the source of radiation is a laser generating a beam creating a hole in the sample and aligning includes adjusting the fiber bundle mount until the illumination spot is concentric with the hole in the sample. 
     
     
         7 . The system of  claim 5  in which aligning further includes focusing the laser beam on the sample and adjusting the fiber bundle mount until the size of the illumination spot is minimized. 
     
     
         8 . The system of  claim 1  in which detecting the presence of a sample includes energizing the illumination source and analyzing any light reflected off the sample. 
     
     
         9 . The system of  claim 8  in which detecting the presence of a sample further includes de-energizing the illumination source and again analyzing any light reflected off the sample. 
     
     
         10 . The system of  claim 9  further including subtracting the light reflected off the sample when the illumination source is de-energized from the light reflected off the sample when the illumination source is energized. 
     
     
         11 . The system of  claim 8  further including inhibiting any radiation from proceeding along the optical emission path if the analysis indicate a sample is not present. 
     
     
         12 . The system of  claim 1  in which localizing includes energizing the illumination source to create an illumination spot at a location on the sample and moving the illumination spot to a desired location on the sample. 
     
     
         13 . The system of  claim 1  in which focusing includes energizing the illumination source to create an illumination spot on the sample and adjusting the focusing lens until the illumination spot size is minimized. 
     
     
         14 . A handheld LIBS spectrometer system comprising:
 a housing;   an optic stage moveable with respect to the housing and including a laser focusing lens;   a laser source mounted in the housing for directing a laser beam to a sample via the laser focusing lens;   a detection fiber bundle mounted in the housing;   a first mirror between the laser source and the focusing lens and including an aperture for the laser beam and oriented to redirect plasma radiation from the sample passing through the focusing lens for delivery to the detection fiber bundle;   a spectrometer subsystem in the housing receiving plasma radiation from the sample via the detection fiber bundle; and   at least one fiber of the fiber bundle connected to a source of illumination for directing light via the mirror and the focusing lens to the sample for alignment, sample presence detection, localization, and/or focusing of the laser beam.   
     
     
         15 . The LIBS spectrometer system of  claim 14  further including a camera aimed at the sample for viewing illumination on the sample. 
     
     
         16 . An analysis system comprising:
 a laser source generating a beam;   an optical emission path for the beam to a sample to create a mark in the sample;   an optical detection path for photons emitted by the sample;   a spectrometer subsystem for analyzing said photons;   a detector fiber bundle for transmitting said photons, to the spectrometer subsystem;   at least one fiber of the fiber bundle connected to an illumination source for directing light via at least a portion of the detection path to the sample creating an illumination spot on the sample; and   an adjustable fiber bundle mount within the housing for aligning the fiber bundle by adjusting the position of the fiber bundle until the illumination spot is concentric with the mark in the sample   
     
     
         17 . The system of  claim 16  in which aligning further includes focusing the laser beam on the sample by adjusting the position of the fiber bundle via the adjustable fiber bundle mount until the size of the illumination spot on the sample is minimized.