Q-switched cavity dumped sub-nanosecond laser
AssigneeCynosure, Inc.
InventorsMirko Mirkov, Henry Zenzie
Life of this patent
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Abstract
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 a sub-nanosecond round trip time.
Claims29
A method of generating sub-nanosecond pulsed laser energy comprising:
- (a) providing a resonator having a first mirror at one end, a second mirror at the opposite end, a lasing medium, a polarizer, and an electro-optic device disposed therebetween, and wherein the resonator has a cavity round trip time of less than 1 nanosecond, and wherein the lasing medium is pumped by a pump source operatively connected to the lasing medium;
- (b) applying a first voltage to the electro-optic device to hold off laser oscillation in the resonator while pumping energy into the lasing medium;
- (c) applying a second voltage to the electro-optic device to build up laser energy within the resonator;
- and
- (d) applying a third voltage to the electro-optic device to cavity dump a portion of the laser energy from the resonator.
A method of generating sub-nanosecond pulsed laser energy and treating pigmented skin comprising:
- (a) providing a resonator having a first mirror at one end, a second mirror at the opposite end, a lasing medium, a polarizer, and an electro-optic device are disposed there between, and wherein the resonator has a cavity round trip time of less than 1 nanosecond, and wherein the lasing medium is pumped by a pump source operatively connected to the lasing medium;
- (b) applying a first voltage to the electro-optic device to hold off laser oscillation in the resonator while pumping energy into the lasing medium;
- (c) applying a second voltage to the electro-optic device to build up laser energy within the resonator;
- (d) applying a third voltage to the electro-optic device to cavity dump a portion of the laser energy from the resonator;
- and
- (e) exposing pigmented skin of a patient to the laser energy with pulses having a duration of at most 990 ps and an energy of at least 10 mJ/pulse.
A method for treating a skin pigmentation comprising generating pulsed laser energy by:
- (a) reflecting laser energy generated by a lasing medium between a first mirror at one end of a resonator and a second mirror at the opposite end of said resonator and through a polarizer and an electro-optical device within the resonator and wherein the resonator has a cavity round trip time of less than 1 nanosecond, and wherein the lasing medium is pumped by a pump source operatively connected to the lasing medium;
- (b) amplifying laser energy within the resonator by applying to the electro-optical device a first constant voltage;
- (c) Q-switching the resonator;
- (d) then cavity dumping the amplified laser energy from the resonator by applying to the electro-optical device a quarter wave voltage Vλ/4;
- and
- (e) exposing pigmented skin of a patient to the pulsed laser energy with pulses having a duration of at most 990 ps and an energy of at least 10 mJ/pulse.
Dependencies are inferred from the claim text.