Patent Number: 
Section: claims

1. A shield for protecting a tool portion having an irradiance damage threshold from high-irradiance radiation from a light source when irradiating a workpiece, said shield arranged between the light source and the tool portion and having an irradiance damage threshold, an absorption coefficient, a volume and a thickness, and designed to absorb in said volume, a portion of said high-irradiance radiation that would otherwise be incident the tool portion, wherein the shield maintains said absorbed high-irradiance radiation below said shield irradiance damage threshold, and wherein radiation exiting the shield and incident the tool portion has an irradiance below the irradiance damage threshold of the tool portion. 2. A shield according to  claim 1 , wherein said shield is arranged between the workpiece and the tool portion. claim 1 3. A shield according to  claim 1 , wherein said shield is made of a partially transmitting glass. claim 1 4. A shield having an irradiance damage threshold I DT  for protecting a tool portion from damage due to high-irradiance radiation I R  from a light source when irradiating a workpiece, said shield arranged between the light source and the tool portion and having a volume damage threshold I DS , an absorption coefficient a, and a thickness t such that an irradiance I ABS  absorbed by said shield from said high-irradiance radiation I R  that would otherwise be incident the tool portion satisfies the condition: I ABS =I R  a (1xe2x88x92exp(xe2x88x92at)) less than I DS ,  and wherein radiation exiting the shield and incident the tool portion has an irradiance I T  which satisfies the condition: I T =I R  (exp(xe2x88x92at)) less than I DT . 5. A shield according to  claim 4 , wherein said shield is arranged between the workpiece and the tool portion. claim 4 6. An apparatus that prevents a tool portion having an irradiance damage threshold from being irradiated by high-irradiance radiation from a light source while irradiating a workpiece, the apparatus comprising: a workpiece support member for supporting a workpiece; and  the shield according to  claim 1  arranged between the light source and the tool portion.  claim 1 7. An apparatus that prevents a tool portion having an irradiance damage threshold I DT  from being irradiated by high-irradiance radiation of irradiance I R  from a light source while irradiating a workpiece, the apparatus comprising: a workpiece support member for supporting a workpiece; and  the shield according to  claim 3  arranged between the light source and the tool portion.  claim 3 8. A workpiece support member for supporting a workpiece having a workpiece outer edge, the workpiece support member being capable of protecting a tool portion having an irradiance damage threshold from high-irradiance radiation while irradiating the workpiece, the workpiece support member comprising: a body with an outer surface and an upper surface with an outer edge, said upper surface capable of supporting the workpiece so that the workpiece outer edge extends beyond said workpiece support member outer edge; and  the shield according to  claim 1  arranged between the workpiece and the tool portion around said outer surface.  claim 1 9. A workpiece support member according to  claim 8 , further including a lip on said workpiece support member body outer surface for supporting said shield. claim 8 10. A workpiece support member for supporting a workpiece having a workpiece outer edge and capable of protecting a tool portion having an irradiance damage threshold I DT  from high-irradiance spillover radiation of irradiance I R  while irradiating the workpiece, the workpiece support member comprising: a body with an outer surface and an upper surface with an outer edge, said upper surface capable of supporting the workpiece so that the workpiece outer edge extends beyond said workpiece support member outer edge; and  A shield according to  claim 3  arranged between the workpiece and the tool portion around said outer surface.  claim 3 11. A workpiece support member according to  claim 10 , further including a lip on said workpiece support member body outer surface for supporting said shield. claim 10 12. A shield for protecting a tool portion having an irradiance damage threshold from high-irradiance radiation from a light source when irradiating a workpiece, said shield arranged between the light source and the tool portion and having an irradiance damage threshold, a scattering coefficient, a volume and a thickness, and designed to scatter in said volume portion of said high-irradiance radiation that would otherwise be incident said tool portion, wherein said shield maintains said scattered high-irradiance radiation below said shield irradiance damage threshold, and wherein radiation exiting the shield and incident the tool portion has an irradiance below the irradiance damage threshold of the tool portion. 13. A shield according to  claim 12 , wherein said shield is arranged between the workpiece and the tool portion. claim 12 14. A shield for protecting a tool portion having an irradiance damage threshold I DT  from damage due to high-irradiance radiation I R  from a light source when irradiating a workpiece, said shield arranged between the light source and the tool portion and separated from the tool portion by a distance d, and having a scattering coefficient "THgr", a scattering area A and a thickness t, wherein radiation exiting the shield and incident the tool portion has an irradiance I T  satisfying the condition: I T =I R  A/("THgr"d 2 ) less than I DT . 15. A shield according to  claim 14 , wherein said shield is arranged between the workpiece and the tool portion. claim 14 16. A shield according to  claim 14 , further having an absorption coefficient a and a shield irradiance damage threshold I DS , and wherein said shield absorbs an irradiance I ABS  given by: claim 14 I ABS =I R  a(1xe2x88x92exp(xe2x88x92at)) less than I DS . 17. A shield according to  claim 12 , wherein said shield comprises one of a turbid media and a opal glass. claim 12 18. An apparatus that prevents a tool portion having an irradiance damage threshold from being irradiated by high-irradiance radiation from a light source while irradiating a workpiece, the apparatus comprising: a workpiece support member for supporting a workpiece; and  the shield according to  claim 12  arranged between the light source and the tool portion.  claim 12 19. An apparatus for irradiating a workpiece with a high-irradiance irradiation I R  and that prevents a tool portion having an irradiance damage threshold I DT  from being irradiated by the high-irradiance radiation, the apparatus comprising: a workpiece support member for supporting a workpiece; and  the shield according to  claim 14  arranged between the light source and the tool portion.  claim 14 20. A workpiece support member for supporting a workpiece having an outer edge and capable of protecting a tool portion having an irradiance damage threshold from high-irradiance radiation otherwise incident the tool portion while irradiating the workpiece, the workpiece support member comprising: a body with an outer surface and an upper surface with an outer edge, said upper surface capable of supporting the workpiece so that the workpiece outer edge extends beyond said workpiece support member outer edge; and  the shield according to  claim 12  arranged between the light source and the tool portion.  claim 12 21. A workpiece support member according to  claim 20 , further including a lip on said outer surface for supporting said shield. claim 20 22. A workpiece support member for supporting a workpiece having an outer edge, capable of protecting a tool portion having an irradiance damage threshold I DT  from high-irradiance radiation of irradiance I R  otherwise incident the tool portion while irradiating the workpiece, the workpiece support member comprising: a body with an outer surface and an upper surface with an outer edge, said upper surface capable of supporting the workpiece so that the workpiece outer edge extends beyond said workpiece support member outer edge: and  the shield according to  claim 14  arranged between the light source and the tool portion.  claim 14 23. A workpiece support member according to  claim 22 , further including a lip on said outer surface for supporting said shield. claim 22 24. A shield for protecting a tool portion having an irradiance damage threshold from high-irradiance radiation from a light source wherein irradiating a workpiece, said shield arranged between the light source and the tool portion and having an irradiance damage threshold, an absorption coefficient, a volume, a scattering coefficient and a thickness, wherein said shield is designed to absorb and scatter in said volume a portion of the high-irradiance irradiation, wherein the shield maintains said absorbed high-irradiance radiation below said shield irradiance damage threshold, and wherein radiation exiting the shield and incident the tool portion has an irradiance below the irradiance damage threshold of the tool portion. 25. A shield according to  claim 24 , wherein said shield is arranged between the workpiece and the tool portion. claim 24 26. A shield according to  claim 24 , wherein said shield comprises opal glass. claim 24 27. A shield for protecting a tool portion having an irradiance damage threshold I DT , from damage due to high-irradiance radiation of irradiance I R  from a light source when irradiating a workpiece, said shield arranged between the workpiece and the tool portion and separated from the tool portion by a distance d, and having an irradiance damage threshold I DS , an absorption coefficient a, a scattering coefficient "THgr", a scattering area A, and a thickness t such that an irradiance I ABS  absorbed by said shield from the high-irradiance radiation satisfies the condition: I ABS =I R  a (1xe2x88x92exp(xe2x88x92at)),  and radiation transmitted through the shield and incident the tool portion has an irradiance I T  satisfying the condition: I T =I R  (exp(xe2x88x92at)) A/(d 2 "THgr"). 28. A shield according to  claim 27  arranged between the workpiece and the tool portion. claim 27 29. An apparatus that prevents a tool portion having an irradiance damage threshold from being irradiated by high-irradiance radiation from a light source while irradiating a workpiece, the apparatus comprising: a workpiece support member for supporting a workpiece; and  the shield according to  claim 24  arranged between the light source and the tool portion.  claim 24 30. An apparatus that prevents a tool portion having an irradiance damage threshold I DT  from being irradiated by high-irradiance radiation from a light source while irradiating a workpiece, the apparatus comprising: a workpiece support member for supporting a workpiece; and  the shield according to  claim 26  arranged between the light source and the tool portion.  claim 26 31. An apparatus supporting a workpiece having an outer edge, capable of protecting a tool portion from high-irradiance radiation otherwise incident the tool portion while irradiating the workpiece, comprising: a body with an outer surface and an upper surface with an outer edge, said upper surface capable of supporting the workpiece so that the workpiece outer edge extends beyond said workpiece support member outer edge: and  the shield according to  claim 24  arranged around said workpiece support member body outer surface and extending beyond the outer edge of said workpiece so as to intercept radiation passing said workpiece outer edge.  claim 24 32. An apparatus according to  claim 31 , further including a lip on said workpiece support member body outer surface for supporting said shield. claim 31 33. An apparatus supporting a workpiece having an outer edge, capable of protecting a tool portion from high-irradiance radiation otherwise incident the tool portion while irradiating the workpiece, comprising: a body with an outer surface and an upper surface with an outer edge, said upper surface capable of supporting the workpiece so that the workpiece outer edge extends beyond said workpiece support member outer edge: and  the shield according to  claim 26  arranged around said workpiece support member body outer surface and extending beyond the outer edge of said workpiece so as to intercept radiation passing said workpiece outer edge.  claim 26 34. An apparatus according to  claim 33 , further including a lip on said outer surface. claim 33 35. A method of attenuating high-irradiance radiation from a light source incident a tool portion of a tool while processing the workpiece, the tool portion having an irradiance damage threshold, the method comprising the steps of: a) arranging a shield between the light source and the tool portion, said shield having a volume and capable of absorbing a portion of the high-irradiance radiation within said volume; and  b) absorbing a portion of the high-irradiance radiation that would be incident the tool portion within said volume of said shield so that radiation leaving said shield and incident said tool portion has an irradiance below the irradiance damage threshold of the tool portion. 36. A method according to  claim 35 , wherein said arranging step a) further includes positioning said shield between the workpiece and the tool portion. claim 35 37. A method of attenuating high-irradiance radiation from a light source incident a tool portion of a tool while processing the workpiece, the tool portion having an irradiance damage threshold, the method comprising the steps of: a) arranging a shield between the light source and the tool portion, said shield having a volume and capable of scattering a portion of the high-irradiance radiation within said volume; and  b) scattering a portion of the high-irradiance radiation that would be incident the tool portion within said volume of said shield so that radiation leaving said shield and incident said tool portion has an irradiance below the irradiance damage threshold of the tool portion. 38. A method according to  claim 37 , wherein arranging step a. further includes positioning said shield between the workpiece and the tool portion. claim 37 39. A method of attenuating high-irradiance radiation from a light source incident a tool portion of a tool while processing the workpiece, the tool portion having an irradiance damage threshold, the method comprising the steps of: a) arranging a shield between the light source and the tool portion, said shield having a volume and capable of absorbing and scattering a portion of the high-irradiance radiation within said volume; and  b) absorbing and scattering a portion of the high-irradiance radiation that would be incident the tool portion within said volume of said shield so that radiation leaving said shield and incident said tool portion has an irradiance below the irradiance damage threshold of the tool portion. 40. A method according to  claim 39 , wherein arranging step a. further includes positioning said shield between the workpiece and the tool portion. claim 39 41. A method of processing a workpiece with high-irradiance radiation from a light source using a tool having a tool portion with an irradiance damage threshold, comprising the steps of: a) supporting the workpiece on a workpiece support member;  b) arranging a shield according to  claim 1  between the light source and workpiece so as to intercept any of the high-irradiance radiation that would otherwise be incident the tool portion; and  claim 1 c) irradiating the workpiece with the high-irradiance radiation. 42. A method of processing a workpiece with high-irradiance radiation from a light source using a workpiece processing tool having a tool portion with an irradiance damage threshold, comprising the steps of: a) supporting the workpiece on a workpiece support member;  b) arranging a shield according to  claim 12  between the light source and workpiece so as to intercept any of the high-irradiance radiation that would otherwise be incident the tool portion; and  claim 12 c) irradiating the workpiece with high-irradiance radiation. 43. A method of processing a workpiece with high-irradiance radiation from a light source using a workpiece processing tool having a tool portion with an irradiance damage threshold, comprising the steps of: a) supporting the workpiece on a workpiece support member;  b) arranging a shield according to  claim 24  between the light source and workpiece so as to intercept any of the high-irradiance radiation that would otherwise be incident the tool portion; and  claim 24 c) irradiating the workpiece with high-irradiance radiation.