Picosecond laser apparatus and methods for treating target tissues with same
Apparatuses and methods are disclosed for applying laser energy having desired pulse characteristics, including a sufficiently short duration and/or a sufficiently high energy for the photomechanical treatment of skin pigmentations and pigmented lesions, both naturally-occurring (e.g., birthmarks), as well as artificial (e.g., tattoos). The laser energy may be generated with an apparatus having a resonator with the capability of switching between a modelocked pulse operating mode and an amplification operating mode. The operating modes are carried out through the application of a time-dependent bias voltage, having waveforms as described herein, to an electro-optical device positioned along the optical axis of the resonator.
1. A method of treating a target tissue comprising:
generating, using a laser source, an output beam having a subnanosecond pulse duration;
modifying the output beam, using an optical system, to provide a photomechanically disruptive treatment beam;
directing the photomechanically disruptive treatment beam to one or more regions of dermal pigmentation;
photomechanically disrupting the one or more regions of dermal pigmentation; and
decreasing visible appearance of the dermal pigmentation in response to the treatment beam.
2. The method of claim 1 , wherein the one or more regions comprise café au lait macules.
3. The method of claim 1 , wherein the one or more regions comprise melanocytic nevi.
4. The method of claim 3 wherein the melanocytic nevi are flat macules.
5. The method of claim 3 wherein the melanocytic nevi are raised papules.
6. The method of claim 1 , wherein the dermal pigmentation is in response to dermal melanocytosis.
7. The method of claim 6 wherein the dermal melanocytosis is congenital dermal melanocytosis.
8. The method of claim 1 , wherein the one or more regions is a pigmented birthmark or portions thereof.
9. The method of claim 8 , wherein the pigmented birthmark or the portion thereof is defined by a wavy border and/or an irregular shape.
10. The method of claim 1 , wherein photomechanically disrupting the one or more regions further comprises photomechanically disrupting pigment particles disposed therein.
11. The method of claim 1 , wherein the treatment beam has a non-uniform profile.
12. The method of claim 11 , wherein the non-uniform profile comprises a plurality of regions of relatively high energy per unit area dispersed within a substantially uniform background region of relatively low energy per unit area.
13. The method of claim 11 further comprising increasing temperature of a first region of scar tissue to a first temperature T1 and increasing or maintaining temperature of a second region of scar tissue to a second temperature T2 using the non-uniform distribution of the treatment beam.
14. A method of treating a target tissue comprising:
generating, using a laser source, an output beam having a subnanosecond pulse duration;
modifying the output beam, using an optical system, to provide a photomechanically disruptive treatment beam;
directing the photomechanically disruptive treatment beam to one or more pigmented lesions;
photomechanically disrupting the one or more pigmented lesions; and
decreasing visible appearance of the one or more pigmented lesions in response to the treatment beam.
15. The method of claim 14 , wherein the pigmented lesions are in response to one or more of: a hormonal change, an infection, or treatment with one or more pharmaceutical agents.
16. The method of claim 14 , wherein the pigmented lesions are in response to melasma and/or chloasma facies.
17. The method of claim 14 , wherein the pigmented lesions are in response to postinflammatory hyperpigmentation.
18. The method of claim 14 , wherein the pigmented lesions are in response to drug-induced pigmentation.
19. The method of claim 14 , wherein the pigmented lesions are in response to ochronosis.
20. The method of claim 14 , wherein the pigmented lesions are in response to an accumulation of homogentisic acid.
21. The method of claim 14 , wherein the treatment beam has a non-uniform profile.
22. The method of claim 21 , wherein the non-uniform profile comprises a plurality of regions of relatively high energy per unit area dispersed within a substantially uniform background region of relatively low energy per unit area.
23. The method of claim 21 further comprising increasing temperature of a first region of scar tissue to a first temperature T1 and increasing or maintaining temperature of a second region of scar tissue to a second temperature T2 using the non-uniform distribution of the treatment beam.
24. A method of treating a target tissue comprising:
generating, using a laser source, an output beam having a subnanosecond pulse duration;
modifying the output beam, using an optical system, to provide a photomechanically disruptive treatment beam;
directing the photomechanically disruptive treatment beam to one or more regions of melasma and/or chloasma facies;
photomechanically disrupting the one or more regions of melasma and/or chloasma facies; and
decreasing visible appearance of the one or more regions of melasma and/or chloasma facies in response to the treatment beam.
25. The method of claim 24 , wherein the treatment beam has a non-uniform profile.
26. The method of claim 25 , wherein the non-uniform profile comprises a plurality of regions of relatively high energy per unit area dispersed within a substantially uniform background region of relatively low energy per unit area.
27. The method of claim 25 further comprising increasing temperature of a first region of scar tissue to a first temperature T1 and increasing or maintaining temperature of a second region of scar tissue to a second temperature T2 using the non-uniform distribution of the treatment beam.