F + 2 -like color center lasers based on oxygen/sodium double-doped alkali halides

Recently F 2 +-like defects have been produced in O 2 −-doped NaCI, KCI, KBr, and RbCl hosts, leading to Nd:YAG-pumped stable color center laser operation over a combined tuning range from 1.45 to 2.16 μm.1 The laser active defects can be regarded as F 2 + centers attached in different possible configurations to a neighboring O−2 ion which replaces a halogen ion. They have been termed ( F 2 + ) H centers.