ISSN (print):1855-9913 | ISSN (web): 1855-9921
High Fluence, High Beam Quality Q-Switched Nd:YAG Laser with Optoflex Delivery System for Treating Benign Pigmented Lesions and Tattoos
Boris Cencic, Matjaz Lukac, Marko Marincek, Zdenko Vizintin
Q-switched neodymium (Nd:YAG) lasers are very effective in the treatment of benign pigmented lesions and tattoos. For effective and safe clearance or eradication of pigments an Nd:YAG laser system must be able to deliver nanosecond pulses with a very high pulse energy, and a uniform beam profile. However, a host of technical challenges are associated with Q-switched Nd:YAG lasers which are capable of sufficiently high energies at short, nanosecond laser pulses. The optical components of a Q-switched laser are exposed to extremely high (several hundred MW) powers that are very close to, or above, their damage thresholds. In addition, high powers may lead to optical breakdown and plasma formation in the air, thereby reducing transmission and deforming the beam. For these reasons, some commercially available devices use a rapid sequence of two, or more, low power laser pulses, instead of a single giant pulse, to increase the total delivered laser fluence to the treated tissue without increasing the instantaneous laser pulse power. In this paper, we report on a study in which the efficacy of pigment clearance by a single giant pulse was compared to the efficacy of clearance under multiple pulse conditions. Results are presented that show that multiple pulsing is not effective, and that high-power, single pulses are mandatory for effective pigment removal. Further, a novel laser delivery approach is described that enables reliable delivery of giant laser pulses with very high beam quality.