Laser scanning system

1 . A method of scanning a laser over a field of view, the method comprising:

providing a laser to produce a laser beam;

rasterizing the laser beam over a first sub-area of the field of view;

deflecting the laser beam to a second sub-area of the field of view;

rasterizing the laser beam over the second sub-area of the field of view;

capturing image information produced by the laser beam so that, for each sub-area of the field of view, the rasterized laser beam defines a plurality of image segments, wherein each of the first sub-area and the second sub-area comprises a number of rows of the image information, and wherein each of the image segments comprises a plurality of said rows;

for each image segment, calculating an image correction and applying a correction to the laser according to the calculated image correction for the image segment; and

applying a time stamp to each correction and/or each image segment and providing a time correlation between the image segments and the corrections to provide a time multiplexed approach to corrections.

2 . The method according to claim 1 , further comprising the step of applying the correction at a time when the corresponding image segment is being scanned by the laser.

3 . The method according to claim 1 , wherein calculating an image correction comprises deriving a wavefront mask, wherein each correction comprises a corresponding wavefront mask.

4 . The method according to claim 1 , wherein calculating an image correction comprises, for each image segment, applying an iterative image-based wavefront sensing loop.

5 . The method according to claim 1 , wherein rasterizing the laser beam comprises moving the laser beam in a first direction corresponding to an x-axis and in a second direction corresponding to a y-axis, wherein the movement of the laser beam in the first direction of the x-axis is faster than the movement of the laser beam in the second direction of the y-axis.

6 . The method according to claim 5 , wherein deflecting the laser beam to the second sub-area of the field of view comprises deflecting the laser beam in a direction of the y-axis.

7 . The method according to claim 5 , wherein a deformable mirror is synchronized with movement of the laser beam in the y-axis.

8 . The method according to claim 5 , wherein each image segment is associated with a unique portion of the x-axis and the y-axis, such that the image segments substantially cover the field of view.

9 . The method according to claim 1 , further comprising time registering each of the image segments and each of the corrections.

10 . A system for scanning a laser beam over a field of view, the system comprising:

a laser for producing the laser beam;

a first moveable deflector for rasterizing the laser beam over a first sub-area of the field of view;

a second moveable deflector for deflecting the laser beam so that the first moveable deflector rasterizes a second sub-area of the field of view;

an image digitizer for digitizing image information produced by the laser beam interacting with a target;

a computer processor for capturing image information produced by the image digitizer so that, for each sub-area of the field of view, the rasterized laser beam defines a plurality of image segments, wherein each of the first sub-area and the second sub-area comprises a number of rows of the image information, and wherein each of the image segments comprises a plurality of said rows, wherein the computer processor calculates an image correction for each image segment; and

an optical correction element for applying a correction to the laser beam according to the calculated image corrections, wherein the system is adapted to:

apply a time stamp to each correction and/or each image segment; and

provide a time correlation between the image segments and the corrections to provide a time multiplexed approach to corrections.

11 . The system according to claim 10 , wherein the first moveable deflector for rasterizing the laser beam over the sub-area of the field of view comprises a spinning polygon mirror and a first galvanic mirror; and wherein

the second moveable deflector for deflecting the laser beam to rasterize a second sub-area of the field of view comprises a second galvanic mirror, and

wherein the spinning polygon mirror moves the laser beam in an x-axis and the first galvanic mirror moves the laser beam in a y-axis.

12 . The system according to claim 11 , wherein movement of the second galvanic mirror deflects the laser beam in a direction in the y-axis, thereby deflecting the laser beam to the second sub-area of the field of view.

13 . The system according to claim 10 , wherein the computer processor calculates an image correction for each image segment.

14 . The system according to claim 10 , wherein the processor applies a time stamp to each image segment and each correction.

15 . The system according to claim 10 , wherein the optical correction element is a deformable mirror.

16 . The system according to claim 15 , wherein the deformable mirror is synchronized with movement of the laser beam in one of an x-axis or a y-axis.

17 . A method of scanning a laser beam over a field of view, comprising the steps of:

sequentially raster scanning the laser beam within a plurality of sub-areas of the field of view, wherein the sub-areas are arranged in a first direction of the field of view;

for each sub-area, defining a plurality of image segments, wherein the image segments of a particular sub-area are arranged in a second direction of the field of view perpendicular to the first direction;

capturing image information for each image segment, the image information associated with illumination of the field of view by the laser beam, wherein each of a first sub-area and a second sub-area comprises a number of rows of the image information, and wherein each of the image segments comprises a plurality of said rows;

calculating, for each image segment, an image correction, wherein the image correction is configured to enable a correction to the laser beam when the laser beam is subsequently raster scanned over the corresponding image segment;

applying a time stamp to each correction and/or each image segment; and

providing a time correlation between the image segments and the corrections to provide a time multiplexed approach to corrections.

18 . A method as claimed in claim 17 , further comprising the step of:

subsequently raster scanning the laser beam and, for each image segment, applying the calculated image correction to the laser beam using an optical correction element.

19 . A system for scanning a laser beam over a field of view, the system comprising:

a laser for producing the laser beam;

a first movable deflector for raster scanning the laser beam;

a second movable deflector for deflecting the laser beam to sequentially raster scan a plurality of sub-areas of the field of view, wherein the sub-areas are arranged in a first direction of the field of view;

an image capture means configured to capture image information for each image segment, the image information associated with illumination of the field of view by the laser beam, wherein each of a first sub-area and a second sub-area comprises a number of rows of the image information, and wherein each of the image segments comprises a plurality of said rows; and

a processor configured to:

for each sub-area, define a plurality of image segments, wherein the image segments of a particular sub-area are arranged in a second direction of the field of view perpendicular to the first direction;

capture image information for each image segment, the image information associated with illumination of the field of view by the laser beam;

calculate, for each image segment, an image correction, wherein the image correction is configured to enable a correction to the laser beam when the laser beam is subsequently raster scanned over the corresponding image segment;

apply a time stamp to each correction and/or each image segment; and

calculate a time correlation between the image segments and the corrections to provide a time multiplexed approach to corrections.

20 . A system as claimed in claim 19 , further comprising an optical correction element for modifying the laser beam,

wherein, when subsequently raster scanning the laser beam, the processor is configured to control the optical correction element such as to, for each image segment, apply the image calculated correction to the laser beam.