We have demonstrated laser action in the transition-metal compound LiSrCrF6. A Ti:sapphire laser was employed to pump into the long-wavelength absorption wing in order to mimic the AlGaAs laser-diode wavelengths. Slope efficiencies greater than 30% were order of 3–5%/cm.
Larry K. Smith, Stephen A. Payne, William F. Krupke, Laura D. DeLoach, Robert Morris, E. W. O’Dell, and D. J. Nelson, "Laser emission from the transition-metal compound LiSrCrF6," Opt. Lett. 18, 200-202 (1993)