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1.
Pumping Yb:YAG or Yb:LuAG into the zero-phonon line at 969?nm instead of using the common pump wavelength of 940?nm reduces the heat generation by 32%. In addition to the 3% increase of the Stokes efficiency, this significantly reduces the diffraction losses caused by the thermally induced phase distortions leading to a remarkable increase of the overall efficiency especially of fundamental-mode thin-disk lasers. Using this pumping scheme in an Yb:LuAG thin-disk laser, we achieved 742?W of nearly diffraction limited (M2≈1.5) output power at an unprecedented high optical efficiency of 58.5%. For multimode operation (M2≈15) the maximum optical efficiency of an Yb:YAG thin-disk laser was increased to 72%. 相似文献
2.
Pronin O Brons J Grasse C Pervak V Boehm G Amann MC Kalashnikov VL Apolonski A Krausz F 《Optics letters》2011,36(24):4746-4748
We demonstrate a power-scalable Kerr-lens mode-locked Yb:YAG thin-disk oscillator. It delivers 200 fs pulses at an average power of 17 W and a repetition rate of 40 MHz. At an increased (180 W) pump power level, the laser produces 270 fs 1.1 μJ pulses at an average power of 45 W (optical-to-optical efficiency of 25%). Semiconductor-saturable-absorber-mirror-assisted Kerr-lens mode locking (KLM) and pure KLM with a hard aperture show similar performance. To our knowledge, these are the shortest pulses achieved from a mode-locked Yb:YAG disk oscillator and this is the first demonstration of a Kerr-lens mode-locked thin-disk laser. 相似文献
3.
大口径谐振腔式固体激光定标到足够高功率后,由于非稳定腔内激光不对称振荡导致介质上激光强度横向不均匀,激光提取与介质产热耦合会引起激光输出功率和光束质量在时域上的不稳定性。针对三种激光器构型:Nd:YAG薄片、Yb:YAG薄片和浸入式液冷叠片激光器,通过理论分析与数值模拟揭示了其各自不同的光热耦合机制及其影响因素,给出了激光输出的瞬态演化规律。结果表明,前两种构型中基于激光动力学的光热耦合具有饱和效应,其动力学不稳定性只出现在特定参数区间,可以通过恰当的设计加以避免;第三种构型中动力学不稳定性表现出明显的阈值特征,在强光状态下只能通过减少冷却液吸收系数来抑制。 相似文献
4.
Innerhofer E Südmeyer T Brunner F Häring R Aschwanden A Paschotta R Hönninger C Kumkar M Keller U 《Optics letters》2003,28(5):367-369
We demonstrate a passively mode-locked diode-pumped thin-disk Yb:YAG laser generating 810-fs pulses at 1030 nm with as much as 60 W of average output power (without using an amplifier). At a pulse repetition rate of 34.3 MHz, the pulse energy is 1.75 microJ and the peak power is as high as 1.9 MW. The beam quality is close to the diffraction limit, with M2 < 1.1. 相似文献
5.
Südmeyer T Innerhofer E Brunner F Paschotta R Usami T Ito H Kurimura S Kitamura K Hanna DC Keller U 《Optics letters》2004,29(10):1111-1113
We demonstrate a synchronously pumped high-gain optical parametric oscillator with feedback through a fiber, using a passively mode-locked Yb:YAG thin-disk laser as a pump source. We obtain as much as 19-W average signal power at a wavelength of 1.45 microm in 840-fs pulses and 7.8 W of idler power at 3.57 microm. The repetition rate of the pulses is 56 MHz, and the transverse beam quality of the generated signal is M2 < 1.6. 相似文献
6.
D. Zhang W. H. Peng Q. Lin Y. L. Li Z. H. Tao Q. R. Ruan T. Y. Zhang 《Laser Physics》2011,21(10):1712-1716
We report for the first time, to the best of our knowledge, a Yb:YAG laser operating in a CW on the three-level laser at 968
nm, based on the 2
F
5/2-2
F
7/2 transition, generally used for a 1030 nm emission. The use of a pump module with 16 passes through the crystal allowed the
realization of a Yb:YAG thin-disk laser with 507 mW of continuous wave (CW) output power at 968 nm. Moreover, intracavity
second-harmonic generation (SHG) has also been achieved with a power of 58 mW at 484 nm by using a BiB3O6 (BIBO) non-linear crystal. 相似文献
7.
We present in this Letter experimental results of a Yb:Sc(2)SiO(5) (Yb:SSO) thin-disk laser. To our knowledge, this is the first lasing demonstration of this crystal in thin-disk configuration reported on to date. Preliminary tests regarding the characterization and the laser operation are presented. Two different resonator configurations, a simple linear multimode cavity, and a fundamental-mode folded resonator providing a double pass in the laser crystal were set up. The gain and the small signal gain of the available Yb:SSO sample were calculated using the experimental results of the multimode resonator. The operation in a fundamental-mode resonator with the double pass in the laser crystal led to 9.4 W of output power with an optical efficiency of 25.4%. 相似文献
8.
Brunner F Paschotta R Aus der Au J Spühler GJ Morier-Genoud F Hövel R Moser M Erhard S Karszewski M Giesen A Keller U 《Optics letters》2001,26(6):379-381
We demonstrate a passively mode-locked thin-disk Yb:YAG laser that generates solitonlike pulses with durations that are continuously tunable in a very wide range from 3.3 to 89 ps or from 0.83 to 1.57 ps. The average powers are typically ~12 W . Previously [Opt. Lett. 25, 859 (2000)], only pulse durations in a narrow range near 0.7 ps could be obtained from such lasers because of the effect of spatial hole burning. We achieved this much wider range by constructing a laser cavity with two different angles of incidence on the thin disk, which greatly reduces the effect of spatial hole burning. 相似文献
9.
Optical properties of Cr,Yb:YAG, Cr,Nd:YAG crystals, and composite Yb:YAG/Cr:YAG ceramics self-Q-switched solid-state laser
materials are presented. The merits of these self-Q-switched laser materials are given and the potentials of such lasers can
be chosen by the applications. Cr,Yb:YAG and composite Yb:YAG/Cr:YAG ceramics self-Q-switched laser are conducted. Although
several tens of kW peak power can be obtained with a monolithic microchip Cr,Yb:YAG laser, the experimental results show that
the performance of this laser is limited by the absorption of Cr4+ ions at a pump wavelength of 940 nm and strong fluorescence quenching at high Cr concentration. Composite Yb:YAG/Cr:YAG ceramics
are more suitable to realize high pulse energy and peak power (up to MW level) with optimized lasing and Q-switching parts.
In addition, the instabilities induced by the multi-longitudinal mode competition in Cr,Nd:YAG and Cr,Yb:YAG microchip lasers
are addressed. The different gain bandwidths of Yb:YAG and Nd:YAG play an important role in the instability of the output
laser pulse trains. Stable laser pulses from the Cr,Yb:YAG microchip laser were obtained due to the antiphase dynamics. For
the Cr,Nd:YAG microchip laser, the instability caused by the multi-longitudinal mode competition is an intrinsic property.
Different transverse patterns were observed in Cr,Nd:YAG microchip lasers when a pump beam with larger diameter was used.
Saturated inversion population distribution inside the gain medium plays an important role in the transverse pattern formation.
Different transverse patterns were reconstructed by combining different sets of the Hermite-Gaussian modes. 相似文献
10.
Generation of 15 W femtosecond laser pulse from a Kerr-lens mode-locked Yb:YAG thin-disk oscillator
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We demonstrated a robust power-scalable Kerr-lens mode-locked(KLM) operation based on a Yb:YAG thin-disk oscillator.15-W,272-fs pulses were realized at a repetition rate of 86.7 MHz with an additional Kerr medium and a 2.5 mm hard aperture in the cavity.247-fs pulses with an average power of 11 W could also be obtained by using a 2.4 mm hard aperture.Based on this shorter pulse,high efficient second-harmonic generation(SHG) was performed with a 1.7-mm-long Li B3O5(LBO) crystal.The SHG laser power was up to 5 W with the power fluctuation RMS of 1% measured over one hour. 相似文献
11.
We report an Yb:KYW thin-disk amplifier system that provides ultrashort pulses in the 10-microJ energy range at high repetition rates. The thin-disk concept uses large laser beam cross sections to avoid high peak intensities. Without using a traditional diffraction-grating stretcher, pulse energies of approximately 9 microJ with pulse durations of 280 fs at repetition rates of 200 kHz were generated. 相似文献
12.
The polarization states of 〈111〉-cut Yb:YAG crystal microchip lasers were investigated by pumped with the elliptically polarized
pump beam from fiber-coupled laser-diode. The manipulated polarized lasers were achieved in laser-diode pumped Yb:YAG microchip
laser by controlling the crystalline-orientations in 〈111〉-growth Yb:YAG crystal. Generally elliptically polarized lasers
were obtained in laser-diode pumped Yb:YAG microchip lasers. However, crystalline-orientation manipulated linearly polarized
laser was obtained when six different sites with different crystalline orientations were set to parallel to the major axis
direction of the elliptically polarized pump beam. Six different sites in Yb:YAG crystal were separated with 30° and 90°,
which were responsible for the linearly polarized laser oscillations. Circularly polarized lasers were observed when a Yb:YAG
crystal was aligned to a special position between two sites responsible for linearly polarized laser oscillation. Effects
of the polarization states of pump source on the laser polarization states of Yb:YAG microchip lasers and polarization direction
of different polarized lasers with respect to Yb:YAG crystal rotation was addressed. 相似文献
13.
The Yb:YAG and Yb:YAP crystals have been grown by Czochralski method. The absorption spectra and the fluorescence spectra of Yb:YAG and Yb:YAP crystals have been investigated. It is shown that the Yb:YAG crystal has better laser properties and smaller threshold power than Yb:YAP crystal. In addition, the absorption cross-section of the Yb:YAP crystal is 2.16 times of that of the Yb:YAG crystal,so laser diode pumped Yb:YAG lasing can be easily realized. Because YAP single crystal is anisotropic, it is provided with polarization characteristics. 相似文献
14.
15.
16.
We report a diode-pumped rod-type Yb:YAG laser amplifier operating at 1 kHz. Cryogenic cooling method was adopted to make the Yb:YAG crystal work with four-level behavior. A single-frequency fiber laser acts as the seed in an actively Q-switched Yb:YAG oscillator. The resonator delivers 5.75-mJ pulses at 1 kHz with a pulse duration of approximately 40 ns. The pulses were amplified to 61 mJ in a four-pass rod-type Yb:YAG amplifier with optical-to-optical efficiency of 24% in the main amplifier. The M2 parameter of the output laser is <1.4. 相似文献
17.
Laser-diode pumped heavy-doped Yb:YAG ceramic lasers 总被引:1,自引:0,他引:1
Laser performance of heavy-doped Yb:YAG ceramics was investigated using a two-pass pumping miniature laser configuration. Slope efficiency of 52% and optical-to-optical efficiency of 48% have been achieved for 1-mm-thick YAG ceramic doped with 20 at.% ytterbium ions. Laser spectra of Yb:YAG ceramic and single-crystal lasers were addressed under different intracavity laser intensities. Heavy-doped Yb:YAG ceramic is more suitable for a thin disk laser than a single-crystal with the same Yb(3+)-ion lasants. 相似文献
18.
Investigation of the Emission Cross-sections and the Spectra of (Cr~(4 ), Yb~(3 ) ): YAG Crystal 总被引:2,自引:0,他引:2
l introductionIn recent years, Cr4 --doped crystals have attracted a great deal of attention aspassive Q--,wit,h.,[l~4]. These Cr4 --dOPed crystals include Cr4 : YAG[l'21 ) Cr4 :GSGG[s], Cr4 : YSO['] etc. They have a large absorption cross section and lOwsaturable intensity at the laser wavelength. In comparison with previously usedsaturable absorbers such as dyes['] and LiF: FZ-- [6] cOlor center crystals, Cr4 -dopedcrystals are more photO--chemically and thermally stable and h… 相似文献
19.
The emission and the lifetime data of Cr, Yb: YAG and Yb: YAG were reported. The effective peak stimulated-emission cross section of chromium and ytterbium-co-doped yttrium-aluminum garnets (Cr, Yb: YAG) has been determined to be 8.98 × 10-20 cm2 at room temperature. The luminescence spectrum of Cr, Yb: YAG is the same as that of Yb: YAG. The luminescence lifetime of Cr, Yb: YAG at room temperature is 0.3 ms (Yb: YAG, 1.48 ms ). The causes of the differences in the fluorescence spectra and the stimulated emission cross-section between Yb: YAG and Cr, Yb: YAG crystals were discussed. Also the potential of Cr, Yb: YAG as a self Q- switched laser crystal was discussed. 相似文献
20.
Jun Dong A. Shirakawa K.-I. Ueda A.A. Kaminskii 《Applied physics. B, Lasers and optics》2007,89(2-3):367-376
A theoretical model based on a quasi-four-level system is modified to investigate the effect of Yb concentration on performance
of continuous-wave Yb:YAG microchip lasers by taking into account temperature-dependent thermal population distribution, temperature-dependent
emission cross-section and concentration-dependent fluorescence lifetime, thermal loading, thermal conductivity, and thermal
expansion coefficient. The local temperature rise in Yb:YAG crystal caused by the absorbed pump power plays an important role
in the laser performance of Yb:YAG microchip lasers working at ambient temperature without actively cooling the sample. The
output wavelengths dependent on output coupling, Yb concentration, and pump power level were analyzed quantitatively. The
numerical simulation of Yb:YAG microchip lasers is in good agreement with experimental data. The optimized laser operation
for Yb:YAG microchip lasers is proposed by varying the thickness and output coupling for different Yb concentrations. The
effect of thermal lens, thermal deformation effect, and saturated inversion population distribution inside the Yb:YAG crystal
on performance of heavy-doped Yb:YAG microchip lasers are also addressed.
PACS 42.55.Xi; 42.70.Hj; 42.55.Rz 相似文献