High power CW and Q-switched operation of a diode-side-pumped Nd:YAG 1319-nm laser

We demonstrated the highly efficient continuous wave(CW)and Q-switched infrared laser from a diode- side-pumped Nd:YAG crystal.A CW output as high as 66 W at 1319 nm was achieved under the pump power of 460 W,corresponding to a coversion efficiency of 14.3%.A maximum average power of 8.9 W of TEM_(00) mode was obtained in Q-switched operation at the repetition rate of 8 kHz.The performance of the laser considering the thermal lens effect induced by pump power was also analyzed.     

High-power passively Q-switched Nd:GdVO_4 laser with a reflective graphene oxide saturable absorber

A single output Q-switched Nd:GdVO4 laser with a reflective graphene oxide(GO) saturable absorber was demonstrated. The shortest pulse duration in the Q-switched laser is 115 ns, and the output power ranges from1.23 W at 1.71 MHz to 2.11 W at 2.50 MHz when the pump power rises from 7.40 to 10.90 W with the utilization of GO Langmuir–Blodgett(LB) films based on the convenient and low-cost LB technique. To the best of our knowledge, it is the highest output power in a Q-switched laser with a GO saturable absorber.     

High power diode-pumped 914-nm Nd：YVO_4 laser

<正>A high power continuous-wave(CW) 914-nm Nd:YVO_4 laser at room temperature is presented.Using an end-pumped structure and employing an 808-nm diode-laser as the pump source,the maximum output power of 15.5 W of the 914-nm laser is achieved at the absorbed pump power of 40.2 W,with a corresponding average slope efficiencyη_s=65.6%.To the best of our knowledge,this is the highest output power of diode-pumped 914-nm laser.A beam quality factor M~2=2.8 at the output power of 15 W is measured by using the traveling knife-edge method.     

A Passive Q-Switched Microchip Er/Yb Glass Laser Pumped by Laser Diode

A laser-diode-pumped 1.54-μm passive Q-switched erbium doped glass laser was reported. We utilize a laser diode with wavelength of 973nm to pump a 1-mm Er/Yb co-doped phosphate glass with the erbium and ytterbium concentrations of 1 wt.% and 21 wt.%, respectively. A Co^2＋ ：MgAl2O4 slab crystal was used as a passive Q- switcher. Q-switched pulses with repetition frequency of 800Hz, width of 7.4ns, peak power of 2.2kW and average power of 13.3 m W were obtained when absorbed pump power was 4 75 m W. A sandwich structure of the Q- switched microchip Er/Yb glass laser was demonstrated, which shows shorter pulse width of 6.8 ns. Dependences of pulse duration and repetition frequency on pump power were also investigated.     

Experimental study of continuous-wave and Q-switched laser performances of Ho:YVO4 crystal

In this letter, we report a Ho:YVO4 laser pumped by a 1.94-μm laser in both continuous-wave(CW)and Q-switched modes. The output performance of the Ho:YVO4 laser is compared with different output coupler transmissions. By use of the output coupler transmissions of T =30%, we obtain the maximum CW output power of 3.9 W at 2052 nm, with beam quality factor of M2=1.09 for the absorbed pump power of 12.5 W. For the Q-switched mode, we achieve maximum output energy per pulse of 0.38 mJ and the minimum pulse width of 25 ns, corresponding to the peak power of 15.2 kW.     

Multi-watt Q-switched Nd:YVO_4 laser with GaAs output coupler

A passively Q-switched operation of a diode-pumped Nd.YVO_4 laser is demonstrated, in which a GaAsfilm is used as the saturable absorber as well as the output coupler. At the pump power of 10 W, a stablefundamental-mode average power output of 2.11 W was obtained with a pulse duration of 140 ns, pulseenergy of 76 μJ and pulse repetition rate of 28 kHz. A theoretical analysis that describes the passiveQ-switching dynamics of GaAs is presented.     

Highly efficient cascaded P-doped Raman fiber laser pumped by Nd:YVO4 solid-state laser

A highly efficient cascaded P-doped Raman fiber laser （RFL） pumped by a 1064-nm continuous wave （CW） Nd：YVO4 solid-state laser is reported. 1.15-W CW output power at 1484 nm is obtained while the input pump power is 4 W, corresponding to the power conversion efficiency of 28.8%. The threshold pump power for the second-order Stokes radiation is 1.13 W. The slope efficiency is as high as 42.6%. The experimental results are in good agreement with theoretical ones. Furthermore, the power instability of the P-doped RFL at 1484 nm in an hour is observed to be less than 5%.     

Diode-Pumped Passively Q-Switched Yb：YAG Microchip Laser with a GaAs as Saturable Absorber

A passively Q-switched Yb: YAG microchip laser has been constructed by using a doped GaAs as the saturable absorber as well as the output coupler. At 13.5 W of pump power the device produces high-quality 3.4μJ 52ns pulses at 1030nm with a pulse repetition rate of 7.8 kHz in a TEM00-mode.     

Diode end-pumped 1123-nm Nd:YAG laser with 2.6-W output power

We present a compact and high output power diode end-pumped Nd:YAG laser which operates at the wavelength of 1123 nm. Continuous wave (CW) laser output of 2.6 W was achieved at the incident pump power of 15.9 W, indicating an overall optical-optical conversion efficiency of 16.4%, and the slope efficiency was 18%.     

Highly efficient cascaded P-doped Raman fiber laser pumped by Nd:YVO4 solid-state laser

A highly efficient cascaded P-doped Raman fiber laser(RFL)pumped by a 1064-nm continuous wave (CW)Nd:YVO_4 solid-state laser is reported.1.15-W CW output power at 1484 nm is obtained while the input pump power is 4 W,corresponding to the power conversion efficiency of 28.8%.The threshold pump power for the second-order Stokes radiation is 1.13 W.The slope efficiency is as high as 42.6%.The experimental results are in good agreement with theoretical ones.Furthermore,the power instability of the P-doped RFL at 1484 nm in an hour is observed to be less than 5%.     

Q-Switched Large-Mode-Area Yb-Doped Fibre Laser Using GaAs as Saturable Absorber

A passive Q-switched large-mode-area Yb-doped fibre laser is demonstrated using a GaAs wafer as the saturable absorber. A high Yb doping concentration double-clad fibre with a core diameter of 30μm and a numerical aperture of 0.07 is used to increase the laser gain volume, permitting greater energy storage and higher output power than conventional fibres. The maximum average output power is 7.2W at 1080nm wavelength, with the shortest pulse duration of 580ns and the highest peak power of 161W when the laser is pumped with a 25W diode laser operating at 976nm. The repetition rate increases with the pump power linearly and the highest repetition rate of 77kHz is obtained in the experiment.     

High-repetition-rate 1.5 μm passively Q-switched Er:Yb:YAl_3(BO_3)_4 microchip laser

End-pumped by a 976 nm diode laser,a high-repetition-rate Er:Yb:YAl_3(BO_3)_4 microchip laser passively Q-switched by a Co~(2+):MgAl_2 O_4 crystal is reported.At a quasi-continuous-wave pump power of 20 W,a 1553 nm passively Q-switched laser with the repetition rate of 544 kHz,pulse duration of 8.3 ns,and pulse energy of 3.9 μJ was obtained.To the best of our knowledge,the 544 kHz is the highest reported value for the 1.5 μm passively Q-switched pulse laser.In the continuous-wave pumping experiment,the maximum repetition rate of 144 kHz with the pulse duration of 8.0 ns and pulse energy of 1.7 μJ was obtained at the incident pump power of 6.3 W.     

Diode-Pumped Quasi-Three-Level Passively Q-Switched Nd：GGG Laser with a Codoped Nd,Cr：YAG Saturable Absorber

We demonstrate the first quasi-three-level passively Q-switched Nd：GGG laser at 937nm using a Nd, Cr：YAG crystal as the saturable absorber. The dependences of the average output power, the repetition rate and the pulse width on the incident pump power are obtained. A maximum average output power of 1.18 W with repetition rate of 35kHz and pulse width of 45ns is achieved at an incident pump power of 18.3 W. The corresponding optical-to-optical and slope efficiencies are 6% and 10%, respectively.     

Frequency stabilization of a laser-diode-module-pumped single-frequency Cr,Nd:YAG laser

A single-frequency passively Q-switched laser was constructed,in which a co-doped crystal served as an active element,a mode selector,and a passive Q-switch simultaneously.In order to obtain the frequency instability of 10-6,a stable single-frequency operation was presented and its characteristics were deter mined.The experimental results showed that the stable single frequency could be maintained for half an hour and the linewidth was approximately 530 MHz at a pump power of 13 W.     

Generation of high power laser at 1314 nm from a diode-side-pumped Nd:YLF module

We demonstrate a high power continuous-wave （CW） and acoustic-optically （AO） Q-switched 1314-nm laser with a diode-side-pumped Nd：YLF module. A maximum CW output power of 21.6 W is obtained with a diode pump power of 180 W, corresponding to an optical-to-optical conversion efficiency of 12.0% and a slope efficiency of 16.1%. In the Q-switching operation, a highest pulse energy of 3.8 mJ is obtained at a pulse repetition rate of 1 kHz. The shortest pulse width and maximum single peak power are 101.9 ns and 37.3 kW, respectively.     

Ti: sapphire Laser Pumped Yb: YAG Laser with Cr~(4 ): YAG as a Passive Q-switch

The Ti: sapphire laser pumped Yb: YAG passively- Q-switched laser with Cr~(4 ): YAG as asaturable absorber experiment was performed. The Mira 900 tunable Ti: sapphire laser with anoutput power up to 1 W was used as a pump source. The optical pump system was composed of aspherical lens (f = 75 mm) for focusing the pump beam to a circular spot with a diameter of about50 up, the pumping power was measured to be up to 920 mW. The laser cavity was configured tobe semispherical, and was formed…     

Frequency stabilization of a laser-diode-module-pumped single-frequency Cr,Nd:YAG laser

A single-frequency passively Q-switched laser was constructed, in which a co-doped crystal served as an active element, a mode selector, and a passive Q-switch simultaneously. In order to obtain the frequency instability of 10-6, a stable single-frequency operation was presented and its characteristics were determined. The experimental results showed that the stable single frequency could be maintained for half an hour and the linewidth was approximately 530 MHz at a pump power of 13 W.     

Diode-Pumped Passive Q-Switched 946-nm Nd：YAG Laser with 2.1-W Average Output Power

We demonstrate a diode-pumped passive Q-switched 946nm Nd: YAG laser with a diffusion-bonded composite laser rod and a co-doped Nd, Cr:YAG as saturable absorber. The average output power of 2.1 W is generated at an incident pump power of 14.3 W. The peak power of the Q-switched pulse is 643 W with 80kHz repetition rate and 40.8 ns pulse width. The slope efficiency and optical conversion efficiency are 17.6% and 14.7%, respectively.     

High conversion efficiency,high power density Q-switched fiber laser

An acoustic-optic Q-switched all-fiber laser With a high-repetition-rate, a short pulse width, a wide spectrum, and a high conversion efficiency is experimentally demonstrated. In the laser configuration, a （1＋1）x 1 side-pumping coupler is introduced to perform backward pumping, and a 10/130%tm Yb fiber is adopted. The acoustic-optic component operates in the first direction, achieving a Q-switched pulse with a repetition rate adjustable in the range of 20 kHz-80 kHz. Under a repetition rate of 20 kHz and a pump power of 6.76 W, the fiber laser obtains a highly efficient and stable pulse output, with an average power of 4.3 W, a pulse width of 56 ns, a peak power of 3.83 kW, and a power density of 1.39x 101~ W/cm2. Particularly, the optic-optic conversion efficiency of the laser reaches as high as 64%. Another feature of the pulsed laser is that the high reflection mirror reflects the pump light as well, which brings the secondary absorption of the pump power into the gain fiber.     

Watt-level Pr~(3+):YLF deep red laser pumped by a fiber-coupled blue LD module or a single-emitter blue LD

A power-scaled laser operation of Pr:YLi F4(YLF)crystal at 720.9 nm pumped by a 443.6 nm laser diode(LD)module was demonstrated.The 20 W module was used to pump the Pr:YLF crystal,and a maximum output power of 3.03 W with slope efficiency of 30.04%was obtained.In addition,a 5 W blue LD was also used to pump the Pr:YLF laser,and a maximum output power of 0.72 W was obtained at room temperature.The output power was limited by the wavelength mismatch between the single-emitter LD and the absorption peak of the crystal.