| We examine the quantum mechanics of optically active ions in crystals. Insight is developed which qualitatively explains the shape of the optical absorption and emission spectra of Fe2+ ions in II-VI materials. In addition to a discussion of the relevant theory, this work explores experimental techniques for absorption spectroscopy, laser-induced fluorescence spectroscopy, and upper-state lifetime measurements in detail. The data collected from these experiments are interpreted in the context of the theories developed herein. The theory and data are used to develop a simple model of the temperature dependence of the upper-state lifetime of Fe2+ ions in ZnSe.;We report the demonstration of high-power continuous wave laser oscillation from Fe2+ ions in zinc selenide in detail. Broadband wavelength tuning of an Fe:ZnSe laser is demonstrated using spectrally selective intracavity optics. Additionally, several resonator configurations were briefly tested with the significant result that >1 W power was achieved near 4100 nm..;We report the use of pulsewidth modulation techniques to deliver short, highpeak-power pulses from an Fe:ZnSe laser. The first passively Q-switched Fe:ZnSe laser was successfully demonstrated with average power >600 mW and with pulse widths <60 ns. Additionally, the first modelocked Fe:ZnSe laser was successfully demonstrated with average power of ~200 mW.. |
