LD-pumped actively Q-switched Nd:GdVO4/KTP red laser

LD-pumped actively Q-switched intracavity frequency-doubled Nd:GdVO₄/KTP red laser has been introduced. A maximum red average output power of 0.78 W at 671 nm was obtained at pulse-repetition frequency (PRF) of 15 kHz and the optical conversion efficiency was 6.5%. At the incident pump power of 12 W, the shortest laser pulse occurred at PRF of 15 kHz. Its full-width at half-maximum and the highest peak power were measured to be 35.8 ns and 3.38 kW. The largest single pulse energy of 56.3 μJ was achieved at PRF of 10 kHz. The influence factors on the Q-switched Nd:GdVO₄/KTP red laser have been discussed.     

Diode-pumped Q-switched Nd:GdVO4/KTP green laser formed with a flat–flat resonator

A diode-pumped acousto-optically Q-switched intracavity frequency-doubled Nd:GdVO₄/KTP green laser formed with a flat–flat resonator was demonstrated. 3.05 W of average green output power at pulse repetition frequency (PRF) of 40 kHz was obtained with an optical conversion efficiency of 18.4%, the effective intracavity frequency-doubling efficiency was 57%. At the incident pump power of 15 W, the shortest laser pulse occurred at PRF of 25 kHz with FWHM width of 14 ns, yielding the highest peak power of 7.44 kW; while the largest pulse energy of 0.14 mJ was achieved at PRF of 15 kHz.     

Diode-pumped Q-switched intracavity frequency-doubled Nd:LuVO<Subscript>4</Subscript>/KTP green laser

A simple and compact diode-pumped acousto-optically Q-switched intracavity frequency-doubled Nd:LuVO₄/KTP green laser were demonstrated successfully for the first time. At an incident pump power of 6.5 W, an average output power of 663 mW, a pulse width of 26 ns were obtained with a PRF of 10 kHz. The pulse energy and peak power of the green light were determined to be 66.3 μJ and 2.55 kW, respectively.     

Diode-pumped cw and Q-switched Nd:GdVO4 laser operating at 1.34 μm

A diode-pumped 1.34 m Nd:GdVO₄ laser operating in cw and active Q-switching modes has been demonstrated. 4.15 W of cw output power was obtained at the highest attainable pump power of 12.3 W, resulting in an optical conversion efficiency of 33.7%, the slope efficiency was determined to be 37.6%. In Q-switching operation, a maximum average output power of 2.7 W was generated at pulse repetition frequency (PRF) of 50 kHz, with an optical conversion efficiency of 22% and a slope efficiency of 29.2%. The laser pulses with shortest duration, highest energy and peak power were achieved at PRF of 10 kHz, the parameters being 15 ns, 160 J, and 10.7 kW, respectively. By intracavity frequency-doubling with a type II phased-matched KTP crystal, 0.62 W average power at 0.67 m was produced at a PRF of 15 kHz, the resulting pulse energy, peak power, and pulse width being 41.3 J, 2.2 kW, and 19 ns, respectively. A group of analytical formulae, based on rate equations, are presented to evaluate the operational parameters of an actively Q-switched laser. Calculated results were found to be in close consistency with the experimental data.     

Power scale-up of the diode-pumped actively Q-switched Nd:YVO4 Raman laser with an undoped YVO4 crystal as a Raman shifter

With an undoped YVO₄ crystal as a Raman shifter, we substantially improved the reliability and the output performance of an actively Q-switched 1176-nm Nd:YVO₄ Raman laser. With an incident pump power of 18.7 W, the average power is greater than 2.6 W at 80 kHz. The pulse width of the pulse envelope is shorter then 5 ns with mode-locked modulation. With an incident pump power of 12.7 W, the pulse energy and peak power is higher than 43 μJ and 14 kW at 40 kHz. PACS 42.55.Ye; 42.55.Xi; 42.60.Gd     

Diode end-pumped Q-switched high-power intracavity frequency-doubled Nd:GdVO4/KTP green laser

A diode-laser-array end-pumped acousto-optically Q-switched intracavity frequency-doubled Nd:GdVO₄/KTP green laser, formed with a three-mirror folded resonator, has been demonstrated. With 15 W of pump power incident upon the Nd:GdVO₄ crystal, a maximum average green output power of 3.75 W was obtained at 50 kHz of pulse repetition frequency, giving an optical conversion efficiency of 25%, whereas the effective intracavity frequency-doubling efficiency was determined to be 72%. At the incident pump power of 12.8 W, the shortest laser pulse was achieved at a pulse repetition rate of 10 kHz, the resulting pulse width, single pulse energy, and peak power were measured to be 35 ns, 108 μJ, and 3.1 kW, respectively. Received: 18 May 2000 / Published online: 20 September 2000     

High repetition rate passively Q-switched diode-pumped Nd:YVO4 laser

We demonstrated an efficient and compact, diode-pumped passively Q-switched Nd:YVO₄ laser operation at 1.064 μm wavelength with high repetition rate, using Cr⁴⁺:YAG as saturable absorber, formed with a simple flat–flat resonator. The maximum CW output power of 4.05 W was obtained at the incident pump power of 8 W. For Q-switched operation, the maximum average output power was measured to be 1.4 W with the corresponding repetition rate of 200 kHz, the pulse width of 60 ns when the initial transmission of Cr⁴⁺:YAG crystal was 85%. The shortest pulse width of 12 ns, the largest pulse energy of 36 μJ and the highest peak power of 3 kW were obtained when the Cr⁴⁺:YAG crystal with an initial transmission of 60% was used.     

LD泵浦Nd∶GdVO4/GaAs被动调Q激光器研究

报道了采用大功率半导体激光器端面泵浦Nd∶GdVO4晶体,利用GaAs晶片兼作饱和吸收被动调Q元件和输出耦合镜,实现了1.06 μm激光的被动调Q运转.在泵浦功率为13.9 W时,获得最高平均输出功率为3.6 W,脉冲宽度为252 ns,单脉冲能量为27 μJ以及峰值功率为107 W的激光脉冲.     

Passively Q-switched <Emphasis Type="Italic">a</Emphasis>-cut Nd:YVO<Subscript>4</Subscript> self-Raman laser

A passively Q-switched a-cut Nd:YVO₄ self-stimulating Raman laser using a Cr:YAG saturable absorber has been demonstrated for the first time. The maximum average output power of the self-Raman laser at 1176 nm is 347 mW at the incident pump power of 10 W with a pulse repetition frequency (PRF) of 66 kHz. The pulse width, pulse energy of the 1176 nm are found to be 10 ns and 5.6 μJ. The conversion efficiency from diode laser input power to Raman output power is 3.47%.     

Diode-pumped passively Q-switched intracavity frequency doubled Nd:GdVO4/KTP green laser

A compact diode-pumped passively Q-switched intracavity frequency-doubled Nd:GdVO₄/KTP green-pulse laser was demonstrated, using Cr⁴⁺:YAG as a saturable absorber in a simple flat–flat cavity. With a 5.9 W incident pump power, a passively Q-switched green laser was obtained with an average power of 397 mW, repetition rate of 40 kHz, and pulse width of 40 ns, when the initial transmission of Cr⁴⁺:YAG was 85%. The shortest pulse width of 30 ns, the highest green peak power of 696 W and the maximum pulse energy of 21 μJ were obtained when the initial transmission of Cr⁴⁺:YAG was 70%. Under CW green operation, we obtained 440 mW output power.     

2 ns-pulse, compact and reliable microchip lasers by Nd:YAG/Cr4+ YAG composite crystal

A compact diode-end-pumped passively Q-switched composite Nd:YAG/Cr⁴⁺:YAG laser was demonstrated in this paper. At the incident pump power of 11.8 W, the shortest pulse width of 2.05 ns was obtained, corresponding to average output power of 1.15 W and repetition rate of 17.1 kHz. The single-pulse energy and peak power were estimated to be 67.3 μJ and 32.8 kW, respectively.     

Q-switched NYAB laser end-pumped by a high-power diode-laser array

A diode-laser array end-pumped acousto-optically Q-switched NYAB laser operating at both 1.06 and 0.53 μm has been demonstrated. An average output power of 1.3 W at 1.06 μm at a pulse repetition frequency (PRF) of 60 kHz was obtained with an optical conversion efficiency of 18.1% and a slope efficiency of 21.3%. At the incident pump power of 6.1 W, the 1.06 μm shortest laser pulse was reached at PRF of 20 kHz with FWHM width measured to be 32 ns, yielding a largest pulse energy of 30 μJ, and a highest peak power of 938 W. The attainable maximum average green power was found to be 185 mW, with an optical conversion efficiency of 3%.     

Power scaling of a continuous-wave and passively Q-switched Yb:KLu(WO<Subscript>4</Subscript>)<Subscript>2</Subscript> laser end-pumped by a high-power diode

The power scaling capacity of a diode end-pumped Yb:KLu(WO₄)₂ laser, operating in the continuous-wave (cw) and passively Q-switched regimes, has been investigated. A cw output power of 11.5 W was achieved with an optical-to-optical efficiency of 41% with respect to the incident pump power, while the slope efficiency amounts to 60%. The passively Q-switchedoperation yielded an average output power of 4.3 W at the fundamental wavelength of 1031.7 nm, and 1.15 W of Raman radiation at 1139.3 nm. The total slope efficiency for Q-switched operation was 40%. The highest pulse energy, duration, and peak power were 170 μJ, 2.2 ns, and 77.3 kW for the fundamental radiation, and 51 μJ, 2.3 ns, and 22.2 kW for the Raman radiation. PACS 42.55.Rz; 42.55.Xi; 42.55.Ye     

Continuous-wave and pulsed laser performance of Nd:LuVO4 crystal

Received August 11, 2003 We report continuous-wave and actively Q-switched laser performance achieved with Nd:LuVO4 crystal for the 4F(3/2) --> 4I(1/2) transition (corresponding wavelength of 1065.8 nm) under high-power diode pumping. Continuous-wave output power of 12.55 W is obtained with an optical conversion efficiency of 50.2%. In actively Q-switched operation the average output power reaches 5.42 W at a pulse repetition frequency of 40 kHz with 18 W of pump power incident upon the crystal, yielding an optical conversion efficiency of 30.1%. The pulse energy and peak power reach 138 microJ and 16.2 kW, respectively, at a pulse repetition frequency of 25 kHz under a pump power of 14.2 W; the pulse duration is 8.5 ns.     

Q-switched operation of <Emphasis Type="Italic">a</Emphasis>-cut Ho:YAlO<Subscript>3</Subscript> laser pumped by a diode-pumped 1.91 μm thulium laser

Q-switched operation of a room temperature Ho:YAP laser was resonantly end-pumped by a diode-pumped Tm:YLF laser at 1.91 μm. The CW Ho:YAP laser generated 9.9 W of linearly output at 2119.03 nm with beam quality factor of M ² ∼1.46 with respect to absorbed pump power of 19.16 W, corresponding to an optical-to-optical conversion efficiency of 51.7% and slope efficiency of 60.6%. Under Q-switched operation, the maximum output power of 9.8 W in relation to 10 kHz pulse repetition frequency (PRF) was obtained, however, the maximum peak power of 60 kW at the PRF of 5 kHz was demonstrated. At 5 kHz pulse energies of 1.92 mJ with pulse width of 32 ns was achieved.     

Diode-end-pumped composite Nd:YVO4 yellow laser based on intracavity frequency-doubled self-Raman laser

We report an intracavity frequency-doubled Q-switched self-Raman yellow laser at 587 nm. A composite Nd:YVO₄ crystal was utilized as self-Raman gain medium. The maximum average output power of yellow light obtained was 1.5 W at the incident pump power of 30 W and at a repetition rate of 50 kHz, corresponding to the optical conversion efficiency of 5%. The shortest pulse width, the maximum pulse energy and the highest peak power were measured to be 5.8 ns, 46.7 μJ and 5.9 kW, respectively.     

LD泵浦Nd∶LuVO4/Cr4+∶YAG被动调Q激光器

采用大功率半导体激光器端面泵浦Nd∶LuVO4晶体，利用Cr4+∶YAG晶体作为可饱和吸收元件，实现了1.06 μm激光的被动调Q运转.在泵浦功率为19.1 W时，获得最高平均输出功率为4.58 W，脉冲宽度为84 ns，单脉冲能量为36.6 μJ以及峰值功率为436.2 W的激光脉冲.     

Continuous wave and passively Q-switched laser performance of a composite crystal bonded with three Nd:YVO<Subscript>4</Subscript> single crystals

The laser performance of a composite crystal bonded with three Nd:YVO₄ single crystals has been investigated for the first time as far as we know. The largest continuous wave output power of 2.68 W is obtained at the incident pump power of 6.2 W, giving an optical conversion efficiency of 43.1% and a slope efficiency of 45.9%. For passively Q-switched operation with Cr⁴⁺:YAG of 71% initial transmission, the shortest pulse width of 18.2 ns, the largest single-pulse energy of 19.9 μJ, and the highest peak power of 1.12 kW are achieved, with the pulse repetition rate being 44.9 kHz, at the incident pump power of 6.2 W. The composite crystal can generate more excellent laser performance, when compared with the single crystals.     

6.5-ns actively Q-switched Nd:YVO_4 laser operating at 1.34 μm

With a plano-concave cavity,diode-pumped continuous-wave(CW) and actively Q-switched Nd:YVO4 laser operating at 1.34 μm is demonstrated.Maximum CW output power of 4.76 W and Q-switched average output power of 2.64 W are obtained with output coupler(transmission T = 3.9%).For the Q-switching operation,the theoretically calculated pulse energy and pulse width,with a pulse repetition frequency(PRF) range of 5-40 kHz,coincide with the experimental results.With a T = 11.9% output coupler,the maximum peak power of 24.3 kW and minimum pulse width of 6.5 ns are obtained when the PRF is 10 kHz.To the best of our knowledge,this is the shortest actively Q-switched pulse duration ever obtained in a 1.3-μm Nd-doped vanadate laser.     

Performance of actively Q-switched Nd:LiLuF<Subscript>4</Subscript> crystal end-pumped by a 792 nm laser diode

An efficient laser diode end-pumped continuous-wave (CW) and AO Q-switched laser of Nd:LiLuF₄ crystal with dual central wavelengths of 1053.1 and 1054.7 nm is reported for the first time. The maximum CW output power of 6.22 W was obtained at absorbed pump power of ∼14.6 W with the output transmission of 2%. The optical conversion efficiency is ∼43%, corresponding to a slope efficiency of about 48% with respect to the absorbed pump. For the Q-switched operation, the shortest pulse width of 17 ns was obtained at the pulse repetition frequency (PRF) of 0.5 kHz, resulting in a pulse energy of 2.24 mJ and peak power of 131.8 kW.