A flashlamp-excited dye laser generating light pulses for therapy has a circulator which circulates a gain media through a dye cell. A controller coordinates operation by triggering flashlamps to excite the laser gain media while the circulator is circulating the gain media. This operation enables the effective generation of laser light pulses with a duration of at least one millisecond. The laser pulse is formed from many subpulses. If the flow velocity of dye solution is great enough such that the new solution enters the resonant cavity before the solutions in the cavity are substantially spent, subsequent subpulses are not quenched, enabling the generation of ultra-long effective pulses with high fluences. Specifically, longer effective pulses of up to 50 msec are attainable with energies of up to 50 Joules. These energies enable reasonable spot sizes, which makes the invention relevant to cutaneous as well as deep tissue therapy, for example.
RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 08/835,012, filed Apr. 8, 1997, now U.S. Pat. No. 6,273,883 entitled "Alexandrite Laser System for Treatment of Dermatological Specimens," by Horace Furumoto, et al., which is a continuation of International Application No. PCT/US97/05560, filed Apr. 4, 1997, which claims the benefit of U.S. Provisional Patent Application Serial No. 60/015,082, filed Apr. 9, 1996, the entire teachings of which are incorporated herein by reference.
A method for generating a long effective pulse duration output beam of laser radiation using a flashlamp-excited dye laser is described. A spaced series of excitation pulses is electronically generated using a pulse forming module. The series of excitation pulses are provided to a flashlamp-excited dye laser, which generates an output beam of laser radiation. The output beam is comprised of a series of spaced micropulses of laser radiation which, in combination, provide a long effective pulse duration.
