Xiaowen Chen

Spectroscopic properties and continuous-wave laser operation of Yb:LuPO 4 crystal

For the first time, and to the best of our knowledge, we report a continuous-wave (cw) laser operation of Yb:LuPO₄ crystal, demonstrated at room temperature in a compact plano-concave resonator end pumped by a diode laser. 1.61 W of cw output power around 1039 nm were generated with 2.40 W of pump power at 976 nm absorbed in a 0.3 mm thick crystal, leading to an optical-to-optical efficiency of 67%, whereas the slope efficiency was 75%. Polarized absorption and emission cross-section spectra are also presented and discussed in detail.

Generation of 2.6-mJ 400-kW pulses from a compact Yb:Gd 3 Ga 5 O 12 laser repetitively Q-switched by an acousto-optic modulator

An efficient, acousto-optically Q-switched, and compact Yb:Gd(3)Ga(5)O(12) laser oscillating around 1026 nm is demonstrated, producing an output power of 5.15 W at a pulse repetition rate of 2 kHz, with optical-to-optical and slope efficiencies being 35.8% and 52%, respectively. The generated laser pulses are 6.4 ns in duration (FWHM), with pulse energy and peak power amounting, respectively, to 2.58 mJ and 403 kW.

High-power passively Q-switched Yb:YCa 4 O(BO 3 ) 3 laser with a GaAs crystal plate as saturable absorber

We report on efficient high-power passively Q-switched operation of a Yb:YCa4O(BO3)3 laser with a GaAs crystal plate acting as the saturable absorber. An average output power of 5.7 W at 1032 nm is generated at a pulse repetition rate of 166.7 kHz when the incident pump power is 26.8 W, with a slope efficiency determined to be 24.5%. The averaged pulse energy achieved is roughly 30 μJ and is increased to about 40 μJ when the output coupling used changes from 30% to 50%, while the shortest pulse width is measured to be 153 ns.

High-energy passively Q-switched operation of Yb:GdCa 4 O(BO 3 ) 3 laser with a GaAs semiconductor saturable absorber

High-energy passively Q-switched operation of a Yb:GdCa(4)O(BO(3))(3) laser is demonstrated, with a GaAs crystal plate acting as saturable absorber. An average output power of 1.31 W at 1027 nm is produced at a pulse repetition rate of 1.92 kHz, the resulting pulse energy, duration, and peak power being respectively 0.68 mJ, 9.0 ns, and 75.6 kW. The shortest pulse duration obtained is 4.9 ns; whereas the maximum pulse energy achievable amounts to 0.83 mJ, which proves to be nearly one order of magnitude higher than ever generated from Yb or Nd lasers passively Q-switched by a GaAs saturable absorber.

Columnar crystal of Yb:LuPO 4 for high-power miniature rod lasers

We report, for the first time to our knowledge, on the laser performance of a sort of miniature columnar Yb:LuPO4 crystal grown from spontaneous nucleation in high-temperature solution. With a very compact resonator longitudinally pumped by a 976-nm diode laser, continuous-wave laser operation is demonstrated with a 2-mm long tiny crystal rod, with output coupling changed over a wide range from 0.5% to 62%, generating a maximum output power of 5.3 W with an optical-to-optical efficiency of 40%, while the slope efficiency being 50%.

Passively Q-switched operation of an Yb:CNGG disordered garnet laser with a GaAs crystal plate as the saturable absorber

Efficient stable passively Q-switched operation of an Yb:CNGG disordered garnet laser is demonstrated with a GaAs crystal plate as the saturable absorber. An average output power of 1.76 W is produced at a pulse repetition rate of as high as 166.7 kHz, with optical-to-optical and slope efficiencies of 23.2 and 33%, respectively. The shortest pulse duration achieved was 99.5 ns.

Passively Q-Switched Yb:YCa 4 O(BO 3 ) 3 /GaAs Laser Generating 1 mJ of Pulse Energy

A compact high-energy Yb:YCOB laser passively Q-switched with a GaAs saturable absorber is demonstrated, producing an average output power of 1.02 W at 1022.7 nm, at a pulse repetition rate of 1 kHz, with pulse energy, duration, and peak power being, respectively, 1.02 mJ, 13.6 ns, and 75 kW.

Continuous-wave and passive Q-switching laser performance of Yb:YSGG crystal

We report, for the first time, on the passive Q-switching laser performance of Yb:YSGG disordered garnet crystal. An average output power of 2.6 W at 1025.8 nm was produced at a pulse repetition rate of 11 kHz with a slope efficiency of 47%; the resulting pulse energy, duration, and peak power were respectively 236 μJ, 3.6 ns and 65.6 kW. The laser performance in continuous-wave mode under 935-nm diode pumping was also investigated, with output coupling changed over a wide range from 0.5% to 60%.

High-energy passively Q-switched laser operation of Yb:Ca 3 La 2 (BO 3 ) 4 disordered crystal

Efficient high-energy passively Q-switched laser operation was demonstrated with Yb:Ca₃La₂(BO₃)₄ disordered crystal, producing an average output power of 3.0 W at 1018.7 nm, at a pulse repetition frequency of 5.0 kHz; the resulting pulse energy, duration, and peak power were 600 μJ, 5.3 ns, and 113.2 kW, respectively.

Continuous-Wave and Passive Q-Switching Laser Performance of Yb:YCa

We have conducted an investigation into the continuous-wave (CW) and passive Q-switching laser performance of the Yb:YCa4O(BO3)3 (Yb:YCOB) crystal, aiming to evaluate its capability of power or energy scaling in compact end-pumped lasers. Efficient CW laser operation was realized with output coupling changed over a wide range from 0.4% to 60%. Operating in CW mode in the long-wavelength sideband around 1085 nm, the Z-cut Yb:YCOB laser produced an output power of 10.7 W with an optical-to-optical efficiency of 56%; in CW operation of the Y-cut Yb:YCOB laser oscillating in the main emission band, an output power of 17.0 W was reached, with optical-to-optical and slope efficiencies being respectively 62% and 78% (with respect to incident pump power). In passive Q-switching regime, the X-cut crystal proved to be the most advantageous in generating high average power and high pulse energy. With a Cr4+:YAG crystal plate serving as saturable absorber whose initial transmission was T0 = 97.5%, and with an output coupling of T = 20%, an average output of 10.72 W was generated at a pulse repetition rate of 26.3 kHz, the resulting pulse duration was 22.3 ns. While under Q-switching operational conditions of T0 = 90.0% and T = 40%, a maximum average output power of 4.13 W could be reached at a rather low repetition rate of 3.23 kHz, yielding a pulse energy that was as high as 1.28 mJ, the resulting pulse duration and peak power being 5.0 ns and 256 kW, respectively.