3d laser ablation tomography and spectrographic analysis

Abstract

A laser ablation tomography system includes a specimen stage for supporting a specimen. A specimen axis is defined such that a specimen disposed generally on the axis may be imaged. A laser system is operable to produce a laser sheet in a plane intersecting the specimen axis and generally perpendicular thereto. An imaging system is operable to image the area where the laser sheet intersects the specimen axis.

We claim: 
     
         1 . A laser ablation tomography system, comprising:
 a specimen stage for supporting a specimen, a specimen axis being defined such that a specimen disposed generally on the axis may be imaged;   a laser system operable to produce a laser sheet in a plane intersecting the specimen axis; and   an imaging system operable to image the area where the laser sheet intersects the specimen axis.   
     
     
         2 . A laser ablation tomography system in accordance with  claim 1 , further comprising:
 a spectrometer;   the laser system being further operable to produce a laser beam to ablate a small area of the specimen, the spectrometer capturing a portion of the light created when the small area is ablated.   
     
     
         3 . A laser ablation tomography system in accordance with  claim 1 , wherein the laser system comprises a laser operable to produce a laser beam and a beam director operable to rapidly scan the laser beam so as to create the laser sheet. 
     
     
         4 . A laser ablation tomography system in accordance with  claim 3 , wherein the laser system further comprises beam shaping optics disposed such that the beam from the laser passes therethrough. 
     
     
         5 . A laser ablation tomography system in accordance with  claim 1 , wherein the laser sheet intersects the specimen axis generally perpendicular thereto. 
     
     
         6 . A laser ablation tomography system in accordance with  claim 1 , further comprising:
 a movement system operable to move the specimen stage along the specimen axis.   
     
     
         7 . A laser ablation tomography system in accordance with  claim 6 , further comprising:
 a control system operable to control the imaging system and the movement system.   
     
     
         8 . A laser ablation tomography system in accordance with  claim 1 , wherein the imaging system comprises a camera with a Charged Coupled Device (CCD). 
     
     
         9 . A laser ablation tomography system in accordance with  claim 1 , wherein the laser system includes a laser, the laser being a short pulsed laser having pulses with a duration less than 10 −6  seconds. 
     
     
         10 . A method for laser ablation tomography, comprising the steps of:
 providing the laser ablation tomography system of any of  claims 1 - 9 ;   positioning a portion of a specimen where the laser sheet intersects the specimen axis;   ablating the specimen with the laser sheet;   imaging the specimen where it was ablated; and   repeating the positioning, ablating and imaging steps.   
     
     
         11 . A method in accordance with  claim 10 , wherein:
 the imaging step is performed during the ablating step.   
     
     
         12 . A method in accordance with  claim 10 , wherein when the positioning step is repeated, the specimen is moved with respect to the laser sheet. 
     
     
         13 . A laser ablation tomography and spectroscopic analysis system, comprising:
 a specimen stage for supporting a specimen, a specimen axis being defined such that a specimen disposed generally on the axis may be imaged and analyzed;   a laser system operable to produce a laser sheet in a plane intersecting the specimen axis, the laser system further operable to produce a laser beam to ablate a portion of the specimen;   an imaging system operable to image the area where the laser sheet intersects the specimen axis, and   a spectrometer operable to capture light from ablation of the portion of the specimen.   
     
     
         14 . A laser ablation tomography and spectroscopic analysis system in accordance with  claim 13 , wherein:
 the laser system has a first mode of operation wherein the laser system produces the laser sheet and a second mode of operation wherein the laser system produces a laser beam for ablating a small area of the specimen;   the spectrometer capturing light from the ablation when the laser system is in the second mode of operation.   
     
     
         15 . A laser ablation tomography and spectroscopic analysis system in accordance with  claim 14 , wherein:
 the laser beam from the laser system in the second mode of operation is generally perpendicular to the plane defined by the laser sheet.   
     
     
         16 . A laser ablation tomography and spectroscopic analysis system in accordance with  claim 14 , wherein:
 the laser system comprises a laser operable to produce a laser beam and a beam director operable in the first mode of operation to rapidly scan the laser beam so as to create the laser sheet and in the second mode of operation to position the laser beam for ablating the small area.   
     
     
         17 . A laser ablation tomography and spectroscopic analysis system in accordance with  claim 16 , wherein:
 the laser system further comprises at least one beam splitter disposed between the specimen stage and the imaging system, the laser beam in the second mode of operation hitting the beam splitter.   
     
     
         18 . A laser ablation tomography and spectroscopic analysis system in accordance with  claim 14 , wherein:
 the imaging system is further operable to capture a location of the ablation when the laser system is in the second mode of operation.   
     
     
         19 . A laser ablation tomography and spectroscopic analysis system in accordance with  claim 14 , wherein:
 the laser system comprises a first laser operable to produce a first laser beam and a second laser operable to produce a second laser beam;   the laser system further comprising a beam director operable in the first mode of operation to rapidly scan the first laser beam so as to create the laser sheet and in the second mode of operation to position the second laser beam for ablating the small area.   
     
     
         20 . A laser ablation tomography and spectroscopic analysis system in accordance with  claim 19 , further comprising:
 a beam splitter positioned where the laser beams from the lasers intersect so that the laser beams share a beam path after the splitter.   
     
     
         21 . A laser ablation tomography and spectroscopic analysis system in accordance with  claim 19 , wherein:
 the first laser is a femtosecond or picosecond laser.   
     
     
         22 . A laser ablation tomography and spectroscopic analysis system in accordance with  claim 21 , wherein:
 the second laser is selected from the group consisting of a short pulsed tunable laser and a continuous laser with narrow bandwidth.   
     
     
         23 . A method for laser ablation tomography and spectroscopic analysis, comprising the steps of:
 providing the laser ablation tomography and spectroscopic analysis system of any of  claims 13 - 22 ;   positioning a specimen on the specimen stage such that a portion of the specimen may be ablated;   ablating the specimen with the laser sheet;   imaging the specimen where it was ablated;   ablating a portion of the specimen with the laser beam;   analyzing the ablated portion of the specimen with the spectrometer; and   repeating the positioning, ablating, imaging and analysing steps.   
     
     
         24 . A laser ablation spectroscopic analysis system, comprising:
 a specimen stage for supporting a specimen, a specimen axis being defined such that a specimen disposed generally on the axis may be imaged and analyzed;   a laser system operable to produce a laser beam to ablate a portion of the specimen;   an imaging system operable to image the area where the laser beam ablates the portion of the specimen; and   a spectrometer operable to capture light from ablation of the portion of the specimen.