Output power saturation in high current regions of different noble-gas ion lasers

Detailed experiments with cw noble gas ion lasers in high current regions are reported. Optimum lasing conditions and saturation behaviour of individual laser transitions in singly and doubly ionized argon, krypton, and xenon have been investigated. Various saturation mechanisms are discussed, such as resonance-radiation trapping, collisional deexcitation, multiple ionization, radial and axial gas pumping, and optical degradation of the cavity mirrors. The experimental results indicate that resonanceradiation trapping is the most probable cause of power limitation in noble-gas ion lasers.