Continuous-wave laser oscillation with extended tuning range in FA(II)-FB(II) color-center crystals.

By using double-doped or mixed-host crystals, an enlargement of the emission range of FA(II)–FB(II) color-center crystals is achieved. We report on cw laser oscillation with FA(II)–FB(II) color centers simultaneously created in the same host crystal. By use of Li+:Na+-doped KCl and RbCl crystals, an extended tuning range has been achieved, so the entire spectral range from 2.27 to 3.33 μm can be covered now with only two samples.