Transition metal doped cadmium manganese telluride: A new material for tunable mid-infrared lasing

Relatively new materials for mid-infrared tunable lasing using chromium-dop ed Cd1-xMnxTe and cobalt-doped Cd1-xMnxTe have been developed. Previously, ZnS and ZnSe were used as host materials for chromium to produce mid-infrar ed (MIR) lasing. Compared to these materials, large diameter CdMnTe is easi er to grow (using the Bridgman technique) and can be made more homogeneous. Moreover, the ternary nature of Cd1-xMnxTe offers the unique opportunity t o optimize the optical properties of the material through variation of chem ical composition and lattice parameter. Using Cd0.55Mn0.45Te:Cr, we have de monstrated room temperature lasing from 2.1 to 3.0 mum, and we have demonst rated quasi-continuous wave (cw) lasing. To our knowledge, the observed tun ing range (similar to 840 nm) of Cr2+:Cd0.55Mn0.45Te is the largest ever re ported from a transition metal ion laser. Furthermore, this is the first ti me that a room temperature quasi-cw laser operating at 3 mum has been demon strated using this type of material. Also, preliminary work on Cd0.55Mn0.45 Te:Co indicates its potential for tunable mid-infrared lasing around 3600 n m at cryogenic temperatures. Results from inductively coupled plasma mass s pectrometry (ICP-MS), which determine the concentration of dopant that has been incorporated into the host lattice, will be reported, as will the mate rials characterization and lasing results. The processing issues for optimi zing the laser performance in these material systems will also be discussed .