Single- and multi-wavelength laser operation of a diode-pumped ND:GGG single crystal around 1.33 µm

We report on the first continuous-wave laser operation of a diode-pumped Nd:GGG single crystal at several emission wavelengths in the 1.33 µm spectral domain. Multi-wavelength laser operation at 1324, 1331 and 1337 nm with a maximum laser output power of 1.83 W and a laser slope efficiency of 28.9% for an output coupler transmission of 2.2% is obtained in the free-running regime. By inserting and tilting a 0.1-mm BK7 glass etalon to modulate the losses inside the laser cavity, single wavelength lasing at 1324 nm and 1347 nm are also achieved with maximum output powers of about 0.77 W and 0.41 W as well as laser slope efficiencies of 15.2% and 12.6%, respectively. Further increasing the pump power, based on the position of the etalon leading to the single laser wavelength operation at 1347 nm, stable dual-wavelength laser operation is demonstrated at 1337 and 1347 nm with a maximum output power of 0.61 W.