Extending the wavelength tunability from 2.01 to 2.1 μm and simultaneous dual-wavelength operation at 2.05 and 2.3 μm in diode-pumped Tm:YLF lasers

Abstract(#br)We report on wavelength extension of diode-pumped Tm:YLF crystal lasers. Using specifically coated end-face mirrors, we have achieved a simulataneous dual-wavelength laser at 2.05 and 2.3 μm with a maximum output power up to 1.33 W and slope efficiency of about 9.7% in continuous-wave regime, for the first time to the best of our knowledge. Moreover, using an un-doped YAG etalon for wavelength tuning, the 2.05 μm lasing wavelength can be shifted to as far as 2.1 μm. We believe that it is the first time that a Tm:YLF laser has been wavelength extended to that far. Using a Cr:ZnSe saturable absorber, a passively Q-switched Tm:YLF laser at 2.05 μm has also attained with a maximum average output power of 0.66 W. The shortest pulse width is 91.7 ns at pulse repetition rate of 8.47 kHz. This work has extended the operating wavelengths of Tm 3+ lasers to that in general for Ho 3+ lasers, which could be practically meaningful for various applications