Diode-pumped and tunable laser operation of Tm,Ho-codoped modified CNGG-type disordered crystals

A comparative study of three disordered calcium niobium gallium garnet (CNGG)-type crystals codoped with Tm3+ and Ho3+ ions is performed: (i) without host modifiers (CNGG), (ii) with Li+ cations added (CLNGG), and (iii) with Li+ and La3+ cations added (LCLNGG), all grown by the Czochralski method. The crystals exhibit inhomogeneously broadened luminescence bands extending beyond 2.1 mu m. A diode-pumped Tm,Ho:LCLNGG laser generates 562 mW at 2082 nm with a slope efficiency of 17.4% and a laser threshold of 0.46 W. A continuous wavelength tuning between 1904.1 and 2121.1 nm (tuning range: 217 nm) is achieved with this new garnet compound. The Tm,Ho:LCLNGG crystal is promising for generation of ultrashort pulses from mode-locked lasers emitting above 2 mu m.

Automated summary

This study compares the properties of three different doped calcium niobium gallium garnet crystals and finds that the crystal with added Li+ and La3+ cations exhibits good performance in laser generation and can achieve a wide tuning range of wavelengths.