Diode-pumped neodymium lasers repetitively Q-switched by Cr/sup 4+/:YAG solid-state saturable absorbers (original) (raw)
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Journal of the Optical Society of America B, 2003
A diode-pumped highly efficient Cr 4ϩ :YAG passively Q-switched Nd:GdVO 4 laser formed by a plano-concave resonator has been demonstrated. At the highest attainable absorbed pump power of 11.4 W, 4.05 W of average output power, which was two thirds of the maximum corresponding cw output, was achieved with an optical conversion efficiency of 35.5%, and the slope efficiency was determined to be 46.8%, reaching 85% of the magnitude of its cw counterpart. The resulting shortest pulse duration, single-pulse energy, and peak power were found to be 13 ns, 90 J, and 7 kW, respectively, with a pulse repetition frequency (PRF) of 45 kHz. Two particularly modified resonator configurations were employed; the largest pulse energy and the highest peak power reached were, respectively, 154 J and 11.2 kW at 8.5 W of absorbed pump power. An analytical relation between the PRF and the absorbed pump power is given for a passively Q-switched laser, showing good consistency with experiment with a Nd:GdVO 4 laser. The dependence of the operational parameters on the pump power and on the output coupling was also investigated experimentally. Issues involving the criterion for passive Q switching are discussed in some detail for Cr 4ϩ :YAG passively Q-switched neodymium-doped vanadate lasers.
Proceedings of SPIE - The International Society for Optical Engineering
We have developed all-solid-state continuous-wave diode end-pumped Nd:YAG and Nd:GdVO4 lasers that were passively Q-switched by Cr4+:YAG saturable absorbers. The Nd:YAG laser delivered laser pulses with 138 mJ maximum energy and duration of 42 ns, with 3.3 W average power at 1.06 mm for 13.3 W of pump power at 807 nm. An average power at 1.06 mm of 1.4 W was obtained from Nd:GdVO4 under pumping with 7.2 W power at 808 nm. The pulse energy and the pulse duration were 41 mJ and 40 ns, respectively, which correspond to 1 kW pulse peak power. The laser pulses characteristics are discussed for Cr4+:YAG saturable absorbers with different values of the initial transmission.
Repetitive Q-switching of a CW Nd:YAG laser using Cr/sup 4+/:YAG saturable absorbers
IEEE Journal of Quantum Electronics, 1996
Repetitive &-switching of a CW pumped Nd : YAG laser using a Cr4+ :YAG saturable absorber was achieved for the first time, providing Pulses 80-300 ns wide ( F W m ) 4 t h repetition rates ranging between 2 and 29 kHz. Different ranges of repetition rates and widths are obtained by using absorbers of different optical densities. Satisfactory quantitative description of the experimental results is obtained by a full numerical solution Of the System rate equations according to the theow Of Powell and Wolga. These equations involve the dynamics of the laser population inversion, the absorber state population, and the photon density in the laser cavity.
ASEAN Journal on Science and Technology for Development, 2017
The results in research and development of diode-pumped passively Q-switched Nd:YVO4 lasers are presented with Cr4+:YAG crystal used as an intra-cavity saturable absorber. Using a-cut Nd:YVO4 laser crystals, the passively Q-switched lasers have been successfully developed and provided stable single shortest pulses of 40 ns at the repetition rate of 18.5 kHz, the maximal average output power of 180 mW was achieved corresponding to the optical efficiency of 9% and the slope efficiency of 16%. The dependences of average output power, repetition rate, pulse width and peak power on pump diode power for different transmissions of output mirror are also investigated.
Optics Communications, 2005
We report on the passively Q-switched mode-locking of a quasi-cw (QCW) diode pumped Nd:GdVO 4 laser with Cr 4+ :YAG saturable absorber. We show that by using the QCW pumping high quality Q-switched mode-locking can be easily obtained in the laser even with a simple two-mirror laser cavity configuration. Mode locked pulses with pulse width of about 1 ps at repetition rate variable from 500 MHz to 1 GHz has been obtained.
Passively Q-Switched Yb:YAG Laser with Cr4+:YAG as the Saturable Absorber
Applied Optics, 2001
By using a continuous-wave Ti:sapphire laser as a pumping source, we demonstrated a passively Q-switched Yb:YAG laser at room temperature with Cr(4+):YAG as the saturable absorber. We achieved an average output power of as much as 55 mW at 1.03 mum with a pulse width (FWHM) as short as 350 ns. The initial transmission of the Cr(4+):YAG has an effect on the pulse duration (FWHM) and the repetition rate of the Yb:YAG passively Q-switched laser. The Yb:YAG crystal can be a most promising passively Q-switched laser crystal for compact, efficient, solid-state lasers.
Passive Q Switching of a Diode-Pumped 946-nm Nd:YAG Laser with 1.6-W Average Output Power
Applied Optics, 1998
As much as 1.6-W average output power was emitted in a simple setup from a diffusion-bonded Nd:YAG rod with 70 -100-ns Q-switched pulses at 946 nm and repetition frequencies between 15 and 45 kHz at 22-W incident diode-pump power. A Cr 4ϩ :YAG crystal with a bleachable loss of approximately 2.5% and a length of 0.5 mm was used as a saturable absorber. The extraction efficiency was 47% in comparison with the continuous-wave laser output power of 3.37 W in the free-running regime.
57 mJ with 10 ns passively Q-switched diode pumped Nd:YAG laser using Cr4+:YAG crystal
Optical and Quantum Electronics, 2015
In this paper, a side diode pumped passively Q-switched Nd:YAG laser is presented using a Cr 4? :YAG as saturable absorber. The performance of the Nd:YAG laser in the free-running and Q-switched modes is theoretically and experimentally studied with different output coupler reflectivities and different initial transmissions of Cr 4? :YAG crystals. The optimum reflectivity of the output coupler is found to be 25 % in the Q-switched mode according to the theoretical calculations and experimental results. The initial transmission of Cr 4? :YAG is set to 20 % in order to achieve maximum output energy in a single laser pulse. The experimental results are in good agreement with calculated values. In the Q-switched mode, single pulse output energy is obtained around 57 mJ with 10 ns pulse duration over 1-20 Hz pulse repetition rates. The optical to optical conversion efficiency reaches 14.25 %.
Diode-Side-Pumped Nd: YVO4 Laser Q-Switched with LiF: Saturable Absorber
2005
Abstract—Passive Q-switching (PQS) of a diode-side-pumped Nd: YVO4 laser using a LiF: crystal as a saturable absorber is reported. Using the grazing-incidence cavity geometry, we obtain trains of giant pulses of duration as short as~ 10 ns and peak power of hundreds of watts. The laser efficiency and beam quality in the PQS regime are shown to essentially depend on the cavity arrangement and output coupler reflectivity.