Development of a compact TEA HF oscillator-double amplifier laser system with corona preionization suitable for medical applications

摘要

The development of a TEA HF (SF_6:C_3H_8:He) oscillator-double amplifier laser system with one common switching element and one common power supply unit is presented. All three cavities employ the conventional charge transfer excitation circuit and the surface corona discharge preionization scheme. For each amplifier the small signal gain coefficient go and the saturation energy density E_s are determined and their dependence on the charging voltage and the active gas concentrations is investigated. The performance characteristics of the laser system i.e. maximum output energy, pulse duration, spectral and beam profile evolution through all three stages of the system are given. Additionally, beam propagation measurements through a 150cm long, 250μm core diameter GeO_2 mid-IR fiber are presented.