3D laser ablation tomography
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.
1. A method for generating a 3-D tomographic image of a specimen with laser light, comprising the steps of:
providing a sheet of laser light;
providing an imaging system with an imaging plane co-planar with the laser sheet;
providing a specimen having a specimen axis defined from a fore end of the specimen to an aft end of the specimen, the imaging plane intersecting the specimen axis;
ablating a cross-sectional slice of the specimen at the imaging plane and exposing a cross-sectional surface of the specimen at the imaging plane; and
imaging the cross-sectional surface of the specimen during, before and/or after the laser sheet ablates a cross-sectional slice of the specimen to obtain an image of the cross-sectional surface.
2. A method according to claim 1 , further comprising:
changing a relative position of the laser sheet and the specimen such that the specimen is moved through the laser sheet; and
repeating the ablating step and the imaging step to generate a plurality of images as the specimen is moved through the laser sheet.
3. A method according to claim 2 , wherein the specimen is moved through the laser sheet in a continuous process.
4. A method according to claim 2 , wherein the specimen is moved through the laser sheet in incremental steps.
5. A method according to claim 2 , further comprising the step of stacking the plurality of images to provide a 3D reconstruction of the specimen.
6. A method according to claim 2 , wherein the step of changing the relative positon of the laser sheet and the specimen comprises moving the specimen.
7. A method according to claim 2 , further comprising the step of providing a stage, the stage supporting the specimen, the step of changing the relative position comprising moving the stage.
8. A method according to claim 1 , wherein the imaging plane is generally perpendicular to the specimen axis.
9. A method according to claim 1 , further comprising providing a laser system producing a laser beam, the laser system producing the laser sheet by repeatedly scanning the laser beam along a line.
10. A method according to claim 9 , wherein the laser system further comprises a beam director and the laser sheet is produced by scanning the laser beam using the beam director.
11. A method according to claim 9 , further comprising the step of passing the laser beam through beam shaping optics before producing the laser sheet.
12. A method according to claim 1 , wherein the imaging system comprises a camera with a Charged Coupled Device (CCD).
13. A method according to claim 1 , wherein the laser system includes a laser operable to produce the laser beam, the laser being a short pulsed laser having pulses with a duration less than 10 −6 seconds.
14. A method for generating a 3-D tomographic image of a specimen with laser light, comprising the steps of:
(a) providing a laser beam by a laser system;
(b) producing a laser sheet by repeatedly scanning the laser beam along a line;
(c) providing an imaging system with an imaging plane co-planar with the laser sheet;
(d) providing a specimen having a specimen axis defined from a fore end of the specimen to an aft end of the specimen, the imaging plane intersecting the specimen axis;
(e) ablating a cross-sectional slice of the specimen at the imaging plane thereby exposing a cross-sectional surface of the specimen at the imaging plane;
(f) imaging the cross-sectional surface of the specimen during, before and/or after the laser sheet ablates a cross-sectional slice of the specimen to obtain an image of the cross-sectional surface;
(g) changing a relative position of the laser sheet and the specimen such that the specimen is moved through the laser sheet; and
(h) repeating the ablating step and the imaging step to generate a plurality of images as the specimen is moved through the laser sheet.
15. A method according to claim 14 , further comprising the step of stacking the plurality of images to provide a 3D reconstruction of the specimen.
16. A method according to claim 14 , wherein the specimen is moved through the laser sheet in a continuous process.
17. A method according to claim 14 , wherein the specimen is moved through the laser sheet in incremental steps.
18. A method according to claim 14 , wherein the imaging plane is generally perpendicular to the specimen axis.
19. A method according to claim 14 , wherein the laser system includes a laser operable to produce the laser beam, the laser being a short pulsed laser having pulses with a duration less than 10 −6 seconds.