High-power As-S glass fiber delivery instrument for pulse YAG:Er laser radiation

A 3-μm laser-generation delivery instrument that uses chalcogenide fibers with a unique damage threshold and conical radiation input has been developed for medical applications. A new purification and synthesis scheme has been elaborated that yields fibers with a heterophase inclusion content of less than 104 cm-3. In such fibers the damage threshold is 350 J/cm2 at an average power density of 0.5 kW/cm2 in a YAG:Er laser operating in the repetitive pulse free-running regime with a pulse duration of 350 ms. 1–3 × 104 laser pulses were transmitted at a repetition rate of 3 Hz and an average output power of 1 W under the condition of a 15% decrease in the output power.