Flexible irradiance in laser imaging

1. An optical processing system for processing an input beam for processing a target, the optical processing system comprising:

a beam shaping system configured to receive the input beam and to shape the irradiance profile thereof into a beam shaping system output beam, the beam shaping system including a distortion lens and an optical homogenizer, the optical homogenizer situated to provide an input beam with a substantially uniform intensity profile to the distortion lens; and

an optical imaging system configured to receive the beam shaping system output beam and to image the beam shaping system output beam to a target;

wherein the imaged beam shaping system output beam provides an irradiance profile configured to produce a predetermined temperature profile associated with the target.

2. An apparatus, comprising:

a beam shaping system situated to receive a homogenized input beam and to shape the irradiance profile of the homogenized input beam with a diffuser element into a beam shaping system output beam; and

an optical imaging system situated to receive the beam shaping system output beam and to direct the beam shaping system output beam to a target;

wherein the beam shaping system output beam has a non-uniform irradiance profile at the target with optical power near the edges being greater than the middle so as to produce a uniform temperature profile associated with the target.

3. The apparatus of claim 2 , wherein the diffuser element is a pair of transversely situated 1D diffusers.

4. The apparatus of claim 2 , wherein the diffuser element is a fly's eye array diffuser.

5. The optical processing system of claim 1 , wherein a distance between the target and the optical imaging system is variable.

6. The optical processing system of claim 1 , wherein the optical imaging system includes an objective lens.

7. The optical processing system of claim 1 , wherein the distortion lens is radially symmetric.

8. The optical processing system of claim 1 , wherein the distortion lens includes a pair transversely situated cylindrical distortion lens elements.

9. The optical processing system of claim 1 , further comprising a light source for providing the input beam to the beam shaping system.

10. The optical processing system of claim 1 , wherein the imaged beam shaping system output beam has a square shape perpendicular to an axis of propagation.

11. The optical processing system of claim 1 , wherein the imaged beam shaping system output beam provides additional optical power nearer the edges so as to provide a uniform temperature at the target.

12. The optical processing system of claim 1 , wherein the target is a solder ball grid array and the adaptable irradiance causes a uniform melting thereof.

13. The apparatus of claim 2 , wherein the diffuser element is a 2D diffuser.

14. The apparatus of claim 2 , wherein the non-uniform irradiance profile is non-uniform along perpendicular axes perpendicular to the direction of the beam shaping system output beam at the target.

15. The apparatus of claim 2 , wherein the non-uniform irradiance profile produces a uniform melting of a solder ball grid array target.

16. The apparatus of claim 2 , wherein the non-uniform irradiance profile is a variable non-uniform irradiance profile based on the pattern size or pattern shape of the target.

17. The apparatus of claim 2 , wherein the non-uniform irradiance profile is variable based on a distance between the target and the optical imaging system.

18. A method, comprising:

generating from a laser source a laser beam having an irradiance profile;

homogenizing the irradiance profile of the laser beam with a homogenizer so as to form a homogenized laser beam having a substantially uniform irradiance profile across an axis perpendicular to a propagation axis of the laser beam; and

receiving the homogenized laser beam and adjusting the uniform irradiance profile so as to form an adjusted homogenized laser beam that has a non-uniform irradiance profile such that optical power near an edge is greater than a middle; and

directing the adjusted homogenized laser beam to a target so that the target has a uniform temperature profile based on the non-uniform irradiance profile.