High-peak-power, pulsed CO2 laser light delivery by hollow glass waveguides

Flexible hollow glass waveguides with internal metallic and dielectric coatings have been used to deliver high-peak-power transversely excited atmosphere CO2 laser energy. The straight guide loss is as low as 0.17 dB/m for 1000-mu m-bore guides and 0.46 dB/m for 530-mu m-bore guides propagating the HE11 mode. The loss increases to 0.93 and 1.36 dB/m, respectively, when guides are bent to a radius of 0.25 m. The hollow glass waveguides have been used to deliver pulsed CO2 laser energy successfully with a peak power of 0.7 MW and an energy of 350 mJ per pulse with a gas purge through the hollow core. The delivered average power is as high as 27 W. It is concluded that these waveguides are promising candidates for pulsed CO2 laser delivery in medical and surgical applications. (C) 1997 Optical Society of America.