Juqing Di

Diode-pumped continuous wave and Q-switched operation of Nd:LuAG crystal

The continuous wave (CW) and passively Q-switched performances of Nd:LuAG crystal were demonstrated. With a laser diode as pump source, the CW output power of 2.18 W was obtained under the pump power of 4.62 W, corresponding to the optical conversion efficiency of 47.2% and the slope efficiency of 52.2%. For Q-switching experiments, the shortest pulse width, largest pulse energy, and highest peak power were measured to be 12 ns, 50.6 μJ, and 4.21 kW, respectively.

CW laser properties of Nd:GdYAG, Nd:LuYAG, and Nd:GdLuAG mixed crystals

Three mixed crystals, Nd:GdYAG, Nd:LuYAG, and Nd:GdLuAG, were grown by Czochralski method. We report the continuous-wave (CW) Nd:GdYAG, Nd:LuYAG, and Nd:GdLuAG laser operation under laser diode pumping. The maximum output powers are 4.11, 5.31, and 7.47 W, with slope efficiency of 73.0, 55.3, and 57.1%, respectively. With replacing Lu3+ or Y3+ ions with large Gd3+ ions, the pump efficiency increases.

A passively Q-switched Yb:YAG laser with a single-walled carbon nanotube saturable absorber

A diode-end-pumped passively Q-switched Yb:YAG bulk laser with a single-walled carbon nanotube saturable absorber is presented. A maximum output power of 715 mW has been obtained with a slope efficiency of 15.7%. The minimum pulse width of 88 ns was achieved at a repetition rate of 175 kHz, corresponding to a pulse energy of 4.1 μJ and a peak power of 46.2 W.

A highly efficient diode-pumped passively mode-locked Nd:Lu1.5Y1.5Al5O12 laser

In this letter, a diode-pumped passively mode-locked Nd:Lu1.5Y1.5Al5O12 (Nd:LuYAG) laser is demonstrated for the first time, to the best of our knowledge. With a semiconductor saturable-absorber mirror, a maximum output power of 0.85 W at 1064 nm was obtained under an absorbed power of 8.51 W, corresponding to a high slope efficiency of 44%. The mode-locked pulses were estimated to be 6.6 ps. The results of our experiment show that Nd:LuYAG crystal could be a promising material for diode-pumped ultra-short laser generation.

Crystal growth, spectroscopic and CW laser properties of Nd0.03Lu2.871Gd0.099Al5O12 crystal

Nd0.03Lu2.871Gd0.099Al5O12 (Nd:LuGdAG) crystal was grown by the Czochralski method. The absorption, fluorescence spectra and fluorescence lifetime of Nd:LuGdAG crystal at room temperature were investigated for the first time. We reported the continuous-wave (CW) Nd:LuGdAG laser operation under diode pumping. Output power of 1.43 W at 1064 nm was achieved with a slope efficiency of 34.1%. All the results show that Nd:LuGdAG crystal is a promising laser material.

Spectroscopic analysis and lasing of Er:Lu 1.5 Y 1.5 Al 5 O 12 crystals

A high optical quality erbium-doped LuYAG single crystal has been grown by the Czochralski technique. The segregation coefficient of Er3+ was measured to be 1.05. The absorption and emission spectra were measured at room temperature. The spectroscopic parameters were calculated using the Judd–Ofelt (J-O) theory, and the J-O parameters Ωt (t=2, 4, 6) were found to be 0.89×10−20, 1.64×10−20, 1.23×10−20 cm2, respectively. The emission cross section of the Er3+ 4I13/2→4I15/2 transition were calculated by the Fuchtbauer–Ladenburg formula, and the room-temperature fluorescence lifetime of the Er3+ 4I13/2→4I15/2 transition was measured to be 9.9 ms. Finally, promising laser performance with Er:Yb fiber laser pumping is described.

Diode-Pumped Passively Mode-Locked 1079nm Nd:CaGdAlO

We demonstrate a diode-pumped passively cw mode-locked Nd:CaGdAlO4 laser operating at 1079nm with a semiconductor saturable absorber mirror for the first time to the best of our knowledge. The threshold pump power of the laser is 180mW. A maximum average output power of 93mW is obtained under the pump power of 1.94 W. The pulse duration of the mode-locked pulses is 3.1 ps and the repetition rate is 157 MHz.

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Optical properties of Ho3+-doped Lu3Al5O12 and (Lu,Y)3Al5O12 crystals were investigated and compared. Substitution of Y for Lu in the host garnet Lu3Al5O12 results in broad absorption and emission spectra, and improvements in the laser behavior of Ho3+. Pumped by Tm:fiber laser, a maximum output power of 5.02 and 5.73 W of Ho-doped Lu3Al5O12 and (Lu,Y)3Al5O12 have been obtained, respectively. The center lasing wavelength are 2124.5 and 2123.0 nm for Lu3Al5O12 and (Lu,Y)3Al5O12, respectively.

Laser

We present a laser-diode-pumped passively mode-locked femtosecond disordered crystal laser by using Nd:CaGdAlO4 (Nd:CGA) as the gain medium. With a pair of SF6 prisms to control the dispersion compensation, laser pulses as short as 850 fs at 1079 nm are obtained with a repetition rate of 124.6 MHz. The measured threshold pump power is 1.45 W. A maximum average output power of 122 mW is obtained under the pump power of 5.9 W. These results show that Nd:CGA could be a promising laser medium for generating femtosecond ultrashort pulse at about 1 μm.

Laser performance of holmium-doped Lu3Al5O12 and (Lu,Y)3Al5O12 crystals pumped by Tm:fiber laser

The 1.35 μm fluorescence lifetime from Cr4+-doped YAG crystal was strongly enhanced by doping Yb ions. We demonstrate that Yb ions act as efficient sensitizers of the 3B2 (3T2) → 3B1(3A2) emission of Cr4+ ions. The lifetime enhancement factor depending on Yb concentration was studied. Our results show that the crystal could be used in microchip laser and has a promising potential as an efficient source with the near infrared emission.