Picosecond laser apparatus and methods for its operation and use
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 (e.g., a Pockels cell) positioned along the optical axis of the resonator.
1. A device for treating a pigment particle in human tissue, the device:
providing a pulsed laser, wherein each pulse of the pulsed laser has a pulse laser energy of at least 100 mj and has a pulse duration of less than 1 nanosecond; and
delivering the pulsed laser energy having a wavelength between 660 nm and 1090 nm with a pulse duration that is a multiple of the acoustic transit time required to transit across a targeted pigment particle in human tissue to photomechanically disrupt the pigment particle.
2. The device of claim 1 wherein a targeted pigment particle measures from 1 micron to 10 microns.
3. The device of claim 1 wherein a targeted pigment particle measures 1 micron.
4. The device of claim 1 wherein a targeted pigment particle is in a tattoo.
5. The device of claim 1 wherein a targeted pigment particle is in a birthmark.
6. The device of claim 1 wherein a targeted pigment particle is in a pigmented lesion.
7. The device of claim 1 wherein a targeted pigment particle is in a skin pigmentation.
8. The device of claim 1 wherein each pulse of the pulsed laser has a pulse duration of from 100 ps to 300 ps.
9. The device of claim 1 wherein each pulse of the pulsed laser has a pulse duration of from 100 ps to 500 ps.
10. The device of claim 1 wherein the pulse duration is below twice the acoustic transit time required to transit across a targeted pigment particle in human tissue.
11. The device of claim 10 wherein a targeted pigment particle measures from 1 micron to 10 microns.
12. The device of claim 10 wherein a targeted pigment particle measures 1 micron.
13. The device of claim 10 wherein each pulse of the pulsed laser has a pulse duration of from 100 ps to 300 ps.
14. The device of claim 10 wherein each pulse of the pulsed laser has a pulse duration of from 100 ps to 500 ps.
15. The device of claim 1 wherein the pulse duration is below five times the acoustic transit time required to transit across a targeted pigment particle in human tissue.
16. The device of claim 15 wherein a targeted pigment particle measures from 1 micron to 10 microns.
17. The device of claim 15 wherein a targeted pigment particle measures 1 micron.
18. The device of claim 15 wherein each pulse of the pulsed laser has a pulse duration of from 100 ps to 300 ps.
19. The device of claim 15 wherein each pulse of the pulsed laser has a pulse duration of from 100 ps to 500 ps.
20. The device of claim 1 wherein the pulse duration is from two times to five times the acoustic transit time required to transit across a targeted pigment particle in human tissue.
21. The device of claim 20 wherein a targeted pigment particle measures from 1 micron to 10 microns.
22. The device of claim 20 wherein a targeted pigment particle measures 1 micron.
23. The device of claim 20 wherein each pulse of the pulsed laser has a pulse duration of from 100 ps to 300 ps.
24. The device of claim 20 wherein each pulse of the pulsed laser has a pulse duration of from 100 ps to 500 ps.