摘要：

Fused silica capillaries proved to be a suitablecladding material for liquid core lightguides. Theyhave small diameters, a good mechanical stability and ahigh flexibility. Due to these properties suchlightguides can be used for applications in minimallyinvasive surgery for endoscopical treatments. Filledwith carbontetrachloride (CCl$-4$/), the opticalproperties were investigated spectrometrically and withvarious lasers. The transmission measurements ofstraight and 180 degree bent fibers were performed witha free-running Er:YAG, Er:YSGG, Ho:YAG, and Nd:YAGlaser. Due to an overlap of the refractive indices ofCCl$-4$/ and fused silica between 500 nm and 1micrometer, laser wavelengths in this spectral range,e.g., of the Nd:YAG and the HeNe laser, cannot betransmitted in this lightguide. If the core liquid is amixture of CCl$-4$/ and tetrachloroethylene(C$-2$/Cl$-4$/) the lightguide is transparent from thenear UV (380 nm) up to the NIR (3 micrometer) andconsequently, it is suitable also for the Nd:YAG laser.With the CCl$-4$/-filled fused silica capillariesdistal energy densities up to 30 J/cm$+2$/ wereachieved and thus the ablation threshold of soft tissueis exceeded. !22

展开