The spectroscopic characteristics, different modes of operation, and applications of the recently developed Cr4+-doped laser systems which operate in the near-infrared wavelength regime are discussed. In particular, a detailed account is given of the developments that have taken place in system optimization and ultrashort optical pulse generation in Cr4+:forsterite and Cr4+:YAG lasers producing coherent light outputs around 1.3 and 1.5 e m, respectively. Thermal loading which has limited the production of high-output powers in Cr4 +:forsterite is further addressed and the results of a recent experimental study aimed at minimizing thermal loading in room-temperature Cr4 +:forsterite lasers are presented. In these experiments, a Nd:YAG-pumped Cr4 +:forsterite crystal with a differential absorption coefficient of 0.57 cm−1, produced as high as 900 mW of output power at 15°Cin a resonator with an output coupler of 4.7% transmission. To the author’s knowledge, this represents the highest power performance reported to date from a room-temperature Cr4 +:forsterite laser and increases the prospects of obtaining high, continuous-wave output powers from these systems.