Abstract: Laser is the light amplification by stimulated emission of radiation, and its wavelength is dependent key electronic structures of active ions, especially those in the outmost levels. Up to now, the lasers have been developed for 60 years, and the laser gain crystals have become the most important materials in the laser regimes boosting the development of lasers and applications. Now, the ultrafast pulsed lasers with the advantages of high peak power and ultrafast pulse width have been successfully applied in many important areas, which pushes that the research on the laser crystals suitable for the ultrafast pulsed lasers has become more and more important. The key of researching on the ultrafast laser crystals is the discovery of the physical parameters and the growth of laser crystals with broadband gain spectra. In this review, the disordered laser crystals including more than 10 kinds of crystals grown by our group and others are reviewed, with the beginning of the discussion of physical parameters of spectra of gain media. The crystal growth, crystalline physics and laser devices are included and their pulsed laser results are also presented. We hope this paper can provide some references for the readers.

Key words: disordered laser crystal, ultrafast laser, ultrashort pulse, inhomogeneous broadening