<title>Novel copper hollow waveguides for IR laser radiation</title>

Abstract

Hollow flexible copper waveguides were developed with two types of dielectric layers (Cu<SUB>2</SUB>O and ZnS). Measurements of transmission as a function of coupled power have shown that scattering appears in the Cu<SUB>2</SUB>O dielectric waveguides which give losses affecting the time of the outlet power which can be maintained constant. Beam profile measurements were performed using the perspex cubes and Spiricon beam profile methods. It was shown that the type of dielectric layer and wavelength of transmitted energy have an influence on the beam profile. The ZnS dielectric layer waveguides have a beam profile with larger average amplitude and less modes as compared to that of Cu<SUB>2</SUB>O dielectric layer. The smaller energy per mode of the Cu<SUB>2</SUB>O waveguides compared to that for ZnS makes the application of the perspex cubes method not applicable for beam profile measurements for the Er-YAG laser where the average transmitted energy is smaller than that of the CO<SUB>2</SUB> laser, since the energy per mode is not enough to produce traces. It was shown, from the beam profile measurements made with perspex and Spiricon methods on ZnS dielectric waveguides, that when ER-YAG laser radiation is used, by increasing the energy per pulse, is obtained longer traces in perspex or larger energy per pulse than by increasing the time of irradiation. This can have practical applications for the operation of removing tissue with Er-YAG laser. A method of detection if the maximum average transmitted energy is coupled to the center of cross section of waveguide was developed based on beam profile measurements.