An Off-Axis Negative-Branch Unstable Resonator for a Chemical Oxygen Iodine Laser

Kurzfassung

The DLR is operating a chemical oxygen iodine laser (COIL) of the 10 kW class. The gain medium has the potential to yield laser radiation of high beam quality. But the large cross-section and low small signal gain coefficient of the gain medium makes the use of standard stable and unstable resonators difficult. The talk shows, under what conditions different resonator concepts, like a double-pass hybrid resonator and an off-axis negative branch unstable resonator, can be usefully applied.