A kilowatt diode-pumped solid-state heat-capacity double-slab laser

A kilowatt diode-pumped solid state heat capacity laser is fabricated with a double-slab Nd:YAG. Using the theoretical model of heat capacity laser output laser characteristics, the relationships between the output power, temperature and time are obtained. The slab is 59 x 40 4.5mm(3) in size. The average pump power is 11.2kW, the repetition rate is 1kHz, and the duty cycle 20%. During the running time of 1s, the output energy of the laser has a fluctuation with the maximal output energy at 2.06J, and the maximal output average power is 2.06kW. At the end of the second, the output energy declines to about 50% compared to the beginning. The thermal effects can be improved with one slab cooled by water. The experimental results are consistent with calculation data.

A compact diode-pumped injection seeded Nd : YAG laser with resonance-detection technique

A diode pumped injection seeded single-longitudinal-mode (SLM) Nd:YAG laser is achieved by using the resonance-detection technique in Q-switching operation. The pulsed oscillator laser uses a folded cavity to achieve compact construction. This system operates at 100 Hz and provides over 20 mJ/pulse of single-frequency 1064 nm output. The M-2 values of horizontal and vertical axes are 1.58 and 1.41, respectively. The probability of putting out single-longitudinal-mode pulses is 100%. The 355 nm laser output produced by frequency tripling has a linewidth less than 200 MHz. The laser can run over eight hours continually without mode hopping.

Highly efficient diode side-pumped Nd : YAG ceramic laser with 210W output power

We developed a highly efficient diode side-pumped Nd:YAG ceramic laser with a diffusive reflector as an optical pump cavity. A maximum output power of 211.6W was obtained with an optical -to- optical conversion efficiency of 48.7%. This corresponds to the highest conversion efficiency in the side-pumped ceramic rod. Thermal effects of the Nd:YAG ceramic rod were analyzed in detail through the measurements of laser output powers and beam profiles near the critically unstable region. A M-2 beam quality factor of 18.7 was obtained at the maximum laser output power. (c) 2006 Elsevier Ltd. All rights reserved.

Efficient diode-pumped Yb : Gd2SiO5 laser

An efficient diode-pumped laser was demonstrated by using an ytterbium-doped laser crystal, Yb:Gd2SiO5 (Yb:GSO), wherein Yb3+ ions exhibit the largest ground-state splitting among all the ytterbium-doped crystals. The Yb:GSO laser can be operated at a low pumping threshold, and the most efficient laser occurs around 1088 nm since the corresponding emission band has the largest emission cross section and the lowest thermal population. A slope efficiency of 75% was demonstrated for a continuous-wave Yb:GSO laser at 1094 nm, and self-pulsed lasers were achieved within the tunable range of 1091-1105 nm, which are the longest laser wavelengths achieved for Yb3+ lasers. (c) 2006 American Institute of Physics.

Efficient tunable diode-pumped Yb : LYSO laser

We demonstrated efficient laser action of a new ytterbium-doped oxyorthosilicate crystal Yb:LuYSiO5 ( Yb: LYSO) under high-power diode-pumping. The spectroscopic features and laser performance of the alloyed oxyorthosilicate crystal are compared with those of ytterbium-doped lutetium and yttrium oxyorthosilicates. In the continuous-wave laser operation of Yb: LYSO, a maximal slope efficiency of 96% and output power of 7.8 W were respectively achieved with different pump sources. The Yb: LYSO laser exhibits not only little sensitivity to the pump wavelength drift but also a broad tunability. By using a dispersive prism as the intracavity tuning element, we demonstrated that the continuous-wave Yb: LYSO laser exhibit a continuous tunability in the spectral range of 1014-1091 nm. (c) 2006 Optical Society of America.

Low-threshold diode-pumped Yb3+, Na+: CaF2 self-Q-switched laser

For the first time to our knowledge, the laser performance of Yb3+, Na+-codoped CaF2 single crystals was demonstrated. Self-Q-switched laser operation at 1050nm was observed for 976 nm diode pumping at room temperature. On 5 W of incident power, the repetition rate and width of the self-Q-switched pulses reached 28 kHz and 1.5 mu s, respectively. A maximal slope efficiency of 20.3% and minimal threshold absorbed pump power of 30 mW were respectively achieved with different output couplers, showing the promising application of Yb3+, Na+-codoped CaF2 crystals as compact and efficient solid-state lasers. (C) 2005 Optical Society of America.

Efficient diode-pumped Tm : YALO(3) laser with a pump recycling scheme

By using a pump recycling configuration, the maximum power of 8.1 W in the wavelength range 1.935-1.938 mu m is generated by a 5-mm long Tm:YAlO3 (4 at. %) laser operating at 18 degrees C with a pump power of 24 W. The highest slope efficiency of 42% is attained, and the pump quantum efficiency is up to 100%. The Tm:YAlO3 laser is employed as a pumping source of singly-doped Ho(l%):GdVO4 laser operating at room temperature, in which continuous wave output power of greater than 0.2 W at 2.05 mu m is achieved with a slope efficiency of 9%.

Diode-pumped passively q-switched Nd : YAG ceramic laser with a Cr4+: YAG crystal-satiable absorber

Transparent polycrystalline Nd:YAG ceramics were fabricated by solid-state reactive sintering a mixture of commercial Al2O3,Y2O3, and Nd2O3 powders. The powders were mixed in ethanol and doped with 0.5 wt% tetraethoxysilane, dried, and pressed. Pressed samples were sintered at 1750 degrees C in vacuum. Transparent fully dense samples with average grain sizes of 10 mu m were obtained. The 1 at.% Nd:YAG ceramic was used to research passively Q-switched laser output with a Cr4+:YAG crystal as a saturable absorber. An average output power of 94 mW with a pulse width of 50 ns was obtained when the incident pump power was 750 mW. The slope efficiency was 13%. The pulse energy is 5 mu J, and the peak power is about 100 W.

Diode-pumped Yb : YAG ceramic laser

Transparent polycrystalline Yb:YAG ceramics were fabricated by solid-state reactive sintering a mixture of commercial Al2O3, Y2O3, and Yb2O3 powders. The powders were mixed in ethanol and doped with 0.5 wt% tetraethoxysilane, dried, and pressed. Pressed samples were sintered at 1730 degrees C in vacuum. Transparent fully dense samples with grain sizes of several micrometers were obtained. The phase from 1500 degrees to 1700 degrees C was important for the grain growth, in which the grains grew quickly and a mass of pores were eliminated from the body of the sample. Annealing was an important step to remove the vacancies of oxygen and transform Yb2+ to Yb3+. The 1 at.% Yb:YAG ceramic sample was pumped by a diode laser to study the laser properties. The maximum output power of 1.02 W was obtained with a slope efficiency of 25% at 1030 nm. The size of the lasering sample was 4 mm x 4 mm x 3 mm.

Diode-pumped Yb : GSO femtosecond laser

Compact femtosecond laser operation of Yb:Gd2SiO5 (Yb:GSO) crystal was demonstrated under high-brightness diode-end-pumping. A semiconductor saturable absorption mirror was used to start passive mode-locking. Stable mode-locking could be realized near the emission bands around 1031, 1048, and 1088 nm, respectively. The mode-locked Yb: GSO laser could be tuned from one stable mode-locking band to another with adjustable pulse durations in the range 1 similar to 100 ps by slightly aligning laser cavity to allow laser oscillations at different central wavelengths. A pair of SF10 prisms was inserted into the laser cavity to compensate for the group velocity dispersion. The mode-locked pulses centered at 1031 nm were compressed to 343 fs under a typical operation situation with a maximum output power of 396 mW. (c) 2007 Optical Society of America.