Shuaiyi Zhang

Crystal growth, spectroscopic characterization, and laser operation of Tm/Mg: LiTaO 3 crystal

Tm, Mg co-doped LiTaO3 crystal is grown by the traditional Czochralski method. By analyzing the absorption and emission measurements of the Tm/Mg: LiTaO3 single crystal with the Judd-Ofelt analysis, the intensity parameters Ω2,4,6, transition probabilities, exited state lifetimes, branching ratios, and emission cross-sections were calculated. Non-photorefractive continuous wave laser operation with a Tm/Mg: LiTaO3 single crystal is demonstrated for the first time. We obtained 1.51 W output power at 1.92 μm with a slope efficiency of near 38.5%, which, to the best of our knowledge, are the largest output power and highest slope efficiency obtained for this crystal thus far. The long-term photorefractive effect was also quantitatively analyzed.

High Repetition Rate All-Solid-State Pulsed 2 μm Laser Based on Selenide Molybdenum Saturable Absorber

A kind of saturable absorber (SA) based on layered MoSe₂ nanosheets has been fabricated successfully by an ultrasound-assisted liquid phase exfoliation method. The as-prepared MoSe₂ SA was characterized and employed as Q-switch in a diode-pumped Tm-doped crystalline all-solid-state laser at around 2 <italic>μ</italic>m. A stable passively Q-switched 2 <italic>μ</italic>m laser with a maximum pulse repetition rate of 158 kHz and a minimum pulse width of 520 ns was successfully realized. A maximum average output power of 1.19 W, corresponding to a maximum pulse energy of 12.7 <italic>μ</italic>J and pulse peak power of 21.8 W, has been obtained. It was the first demonstration of MoSe₂ SA in realizing a solid-state 2 <italic>μ</italic>m pulsed laser, to the best of our knowledge. The results confirmed the excellent ability and promising potential of MoSe₂ SA as an optical modulator in generating high repetition rate and short pulsed laser at the midinfrared spectral band.

Passively Q-switched Ho,Pr:LiLuF 4 laser with graphitic carbon nitride nanosheet film

A few-layer graphitic carbon nitride (g-CN) nanosheet film on an yttrium aluminum garnet substrate was fabricated and employed as saturable absorber for a passively Q-switched Ho,Pr:LiLuF4 laser at 2.95 μm. Under an absorbed pump power of 3.89 W at a pump wavelength of 1.15 μm, a maximum average output power of 101 mW was realized with a pulse duration of 420 ns and a repetition rate of 93 kHz. Even shorter pulse durations of 385 ns were obtained at a reduced output coupler transmission.

Exploring the mode-locking laser performance of Yb:LaMgB 5 O 10 crystal

The spectral properties of 5 at.% doped Yb:LaMgB5O10 (Yb:LMB) crystal were presented and discussed in detail. The large absorption and emission cross sections, broad emission spectral lines, and considerably good thermal conductivity indicate the considerable potential of Yb:LMB for efficient and powerful ultrashort laser application. In the experiment, the semiconductor saturable absorber mirror (SESAM) mode-locked Yb:LMB laser generated pulses with the pulse duration of 182 fs and the central wavelength of 1025.2 nm. The maximum average power was 2.49 W with the slope efficiency of 48% and the optical to optical efficiency as high as 32%. Furthermore, pulses of 148 fs with average output power of 1.52 W and 108 fs with 0.61 W were obtained based on Yb:LMB crystal. To the best of our knowledge, this is the first demonstration of mode-locked pulse generation from the Yb:LMB laser.