Treatment of skin by spatial modulation of thermal heating

1. A method for treating skin, the method comprising delivering a beam of radiation to a target region of the skin to cause a zone of thermal injury including a lateral pattern of varying depths of thermal injury distributed along the target region, the lateral pattern including at least one first sub-zone of a first depth of thermal injury laterally adjacent to at least one second sub-zone of a second depth of thermal injury, wherein (i) the first depth is greater than the second depth, (ii) the at least one first sub-zone of the first depth and the at least one second sub-zone of the second depth extend from a surface of the target region of the skin to form a substantially continuous surface thermal injury, and (iii) the at least one first sub-zone of the first depth and the at least one second sub-zone of the second depth are substantially heated to at least a critical temperature to cause the thermal injury.

2. The method of claim 1 wherein the lateral pattern has a substantially sinusoidal cross sectional injury profile.

3. The method of claim 1 further comprising delivering the beam of radiation to the target region to form a one-dimensional lateral pattern of varying depths of thermal injury.

4. The method of claim 1 further comprising delivering the beam of radiation to the target region to form a two-dimensional lateral pattern of varying depths of thermal injury.

5. The method of claim 1 wherein at least one of the first depth and the second depth are between about 2 mm and about 0.02 mm.

6. The method of claim 1 further comprising heating the at least one first sub-zone and the at least one second sub-zone to substantially the same temperature.

7. The method of claim 1 wherein the first depth is about 1.5 mm and the second depth is about 0.05 mm.

8. The method of claim 1 wherein the critical temperature is below about 100° C., 95° C., 90° C., 85° C., 80° C., 75° C., 70° C., 65° C., 60° C., 55° C., or 50° C.

9. The method of claim 1 wherein the thermal injury includes at least one of ablation, coagulation, necrosis, and acute thermal injury of skin.

10. The method of claim 1 further comprising cooling the surface of the skin, to control the surface thermal injury.

11. The method of claim 1 further comprising cooling the surface of the skin, to prevent unwanted surface thermal injury.

12. The method of claim 1 further comprising delivering a beam of radiation having a first wavelength to the at least one first sub-zone to cause the first depth of thermal injury and a beam of radiation having a second wavelength to the at least one second sub-zone to cause the second depth of thermal injury.

13. The method of claim 1 further comprising delivering a beam of radiation having a first fluence to the at least one first sub-zone to cause the first depth of thermal injury and a beam of radiation having a second fluence to the at least one second sub-zone to cause the second depth of thermal injury.

14. The method of claim 1 further comprising delivering a beam of radiation having a first pulse duration to the at least one first sub-zone to cause the first depth of thermal injury and a beam of radiation having a pulse duration to the at least one second sub-zone to cause the second depth of thermal injury.

15. The method of claim 1 further comprising at least two first sub zones of the first depth are separated by a center to center distance of about 0.05 mm to about 20 mm.

16. The method of claim 1 wherein the at least one first sub-zone of the first depth has an aspect ratio of diameter:depth up to about 0.1:10.

17. The method of claim 1 wherein the at least one second sub-zone of the second depth has an aspect ratio of diameter:depth up to about 0.1:10.