Growth, Spectroscopy and Laser Operation of Tm,Ho:CNGG: A Promising Disordered Crystal for Mode-Locked Lasers

Mode-locked (ML) lasers emitting in the spectral range of ~2 μm are based on Thulium (Tm
³⁺
) or Holmium (Ho
³⁺
) ions. The former one typically emits slightly below 2 μm where the atmosphere water vapour absorption can constrain the emission bandwidth of a ML laser. A disordered host material can provide inhomogeneous broadening of the emission spectra beyond 2 μm: recently, a Tm
³⁺
-doped disordered CNGG-type garnet generated 78 fs pulses at 2017 nm [1]. Another route is the use of Tm
³⁺
,Ho
³⁺
codoped materials for further spectral broadening.