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1.
Xiaomei Wang Guiqiu LiShengzhi Zhao Shixia LiDechun Li Kejian YangLu Zhang Haijuan ZhangHongwei Chu Tianli Feng 《Optik》2014
By using a piece of GaAs wafer as the saturable absorber, the performance of the passively Q-switched composite Nd:YVO4 laser with different output couplers has been demonstrated for the first time as far as we know. The largest continuous wave output power of 1.52 W is obtained at the incident pump power of 5.31 W, giving an optical conversion efficiency of 28.7% and a slope efficiency of 30.2%. The shortest pulse width of 11 ns, the largest single-pulse energy of 2.49 μJ and the highest peak power of 190 W are also obtained. 相似文献
2.
In this paper, a stable end-pumped intracavity-frequency-doubled green laser was demonstrated. The interaction length of different pump systems before setting up the experiment was analyzed in order to find out an effective pump system. The experimental results indicate that the pump system in our configuration is beneficial to the efficient CW Nd lasers. A continue-grown composite crystal YVO4/Nd:YVO4, with Nd3+ concentration doping of 0.3 at.%, is used as laser medium. With an incident pump power of 27.5 W, as high as 7.2 W of CW output power at 532 nm was achieved. The optical-to-optical conversion efficiency of 26.2% was obtained in CW modes with a flat-flat cavity design. 相似文献
3.
Yan Zhang Dechun Li Kejian Yang Guiqiu Li Gang Zhang Kang Cheng 《Optics Communications》2010,283(24):5121-5125
By using both acousto-optic (AO) modulator and GaAs saturable absorber, a diode-pumped doubly Q-switched and mode-locked (QML) YVO4/Nd:YVO4 laser is presented. The average output power and the pulse width of the Q-switched envelope have been measured. The Q-switch pulse energy of the doubly QML laser are higher than that only with GaAs. The stability of the QML laser with the dual-loss-modulation is significantly improved if compared to that only with GaAs.The experimental results show that the doubly QML YVO4/Nd:YVO4 laser has nearly 80% modulation depth and deeper than that of the singly passively QML pulse. The doubly Q-switched mode-locked pulse inside the Q-switched envelope has a repetition rate of 111 MHz and its pulse width is estimated to be about 700 ps. By using a hyperbolic secant square function and considering the Gaussian distribution of the intracavity photon density, the coupled equations for diode-pumped dual-loss-modulated QML laser is given and the numerical solutions of the equations are in good agreement with the experimental results. 相似文献
4.
P. Li 《Optics Communications》2010,283(24):5139-5144
By using a simple linear configuration, a stable and efficient YVO4-Nd:YVO4 laser, actively Q-switched by an acousto-optic modulator and passively mode-locked by KLM is realized, from which the great average output power, the high efficiency are obtained and the mode-locked pulse inside the Q-switched pulse has a repetition rate of 470 MHz. The nearly 100% modulation depth of the Q-switched mode-locked pulses can be obtained at any pump power over the threshold. Considering the Kerr-lens effect of laser medium and Q-switching by an acousto-optic modulator, we have analyzed the self-mode-locked YVO4-Nd:YVO4 laser by using the nonlinear ABCD propagation matrix and the hyperbolic fluctuation mechanism. The numerical solutions are in good agreement with the experimental results. 相似文献
5.
Theoretical analysis and experimental research on thermal focal length of a YVO4/Nd:YVO4 composite crystal 下载免费PDF全文
This paper investigates the temperature field distribution and thermal focal length within a laser diode array (LDA) end-pumped YVO4/Nd:YVO4 rectangular composite crystal. A general expression of the temperature field distribution within the Nd:YVO4 rectangular crystal was obtained by analysing the characteristics of the Nd:YVO4 crystal and solving the Poisson equation with boundary conditions. The temperature field distributions in the Nd:YVO4 rectangular crystal for the YVO4/Nd:YVO4 composite crystal and the Nd:YVO4 single crystal are researched respec- tively. Calculating the thermal focal length within the Nd:YVO4 rectangular crystal was done by an analysis of the additional optical path differences (OPD) caused by heat, which was very identical with experimental results in this paper. Research results show that the maximum relative temperature on the rear face of the Nd:YVO4 crystal in the composite crystal is 150 K and the thermal focal length is 35.7 mm when the output power of the LDA is 22 W. In the same circumstances, the experimental value of the thermal focal length is 37.4 mm. So the relative error between the theoretical analysis and the experimental result is only 4.5%. With the same conditions, the thermal focal length of the Nd:YVO4 single crystal is 18.5 mm. So the relative rate of the thermal focal length between the YVO4/Nd:YVO4 crystal and the Nd:YVO4 crystal is 93%. So, the thermal stability of the output power and the beam quality of the YVO4/Nd:YVO4 laser is more advantageous than the laser with Nd:YVO4 single crystal. 相似文献
6.
The luminescent orthovanadate compound YVO4 has been studied by soft X-ray Appearance Potential Spectroscopy. Vanadium L2.3 APS spectra, which give information about unoccupied electron states, have been interpreted in conjunction with existing experimental data on soft X-ray emission and with cluster model calculations. The main features of the APS spectrum of vanadium in YVO4 as compared with the APS spectrum of pure vanadium metal are discussed, as well as the extent to which the vanadium L2.3 APS-signal in YVO4 can be explained by the energy level diagram given by a non-self-consistent calculation in a VO43− cluster model. 相似文献
7.
In this paper, the absorption coefficients αo (for ordinary ray) and αe (for extraordinary ray) of an undoped YVO4 crystal were calculated by measuring the transmissivities and refractive indices. The mean values 0.00549 cm−1 of αo measured by unpolarized light, and 0.00432 cm−1 of αo and 0.00420 cm−1 of αe measured by linear polarized light were reported, respectively. The corresponding absorption curves were given. The discussions about the errors were made. This work is available to evaluate quantificationally the quality of undoped YVO4 crystal and provides the significant data of absorption coefficient for its applications. 相似文献
8.
Thermal effect control is critical to scale the output power of diode end-pumping solid lasers to several watts up and beyond. Diffusion bonding crystal has been demonstrated to be an effective method to relieve the thermal lens for the end-pumping laser crystal. The temperature distribution and thermal lens in Nd:YVO4/YVO4 composite crystal was numerically analyzed and compared with that of Nd:YVO4 crystal in this paper. The end-pumping Nd:YVO4/YVO4 composite crystal laser was set up and tested with z cavity. The maximum output power of 9.87 W at 1064 nm and 6.14 W at 532 nm were obtained at the pumping power of 16.5 W. The highest optical-optical conversion efficiencies were up to 60% at 1064 nm and 40% at 532 nm, respectively. 相似文献
9.
LD泵浦的高效率YVO4/LBO红光激光器 总被引:1,自引:0,他引:1
《光学技术》2001,27(4):365-366
报道了用国产LD泵浦Nd∶YVO4产生的1.342μm的输出.首次用Ⅱ类临界位相匹配LBO腔内倍频实现了671nm的红激光输出.当泵浦注入功率为800mW时,倍频红激光基模输出为52mW,光光转换效率达6.5%.光束经扩束准直后测得偏振比高于100∶1.在输出功率为40mW时,48h连续工作稳定性优于±2%. 相似文献
10.
11.
We report on fundamental and intracavity frequency-doubled emission in a miniature Nd:YVO4 (3×3×1 mm) laser. A maximum slope efficiency of ηs=58.6%, with optical efficiency of η0=53.0% at 780 mW pump power was realized in a TEM00 output beam. To obtain the optimum pump-beam focusing conditions we applied a new formalism in which the pump-beam propagation in the active medium was described by its M2 factor. A good agreement between theoretical predictions and experimental results was observed. In second-harmonic regime, obtained by a KTP crystal, 230 mW green power that corresponds to 54% nonlinear conversion efficiency was reached. 相似文献
12.
13.
YVO4:Eu, and YVO4:Eu/SiO2 nanocrystals (NCs) were prepared by hydrothermal method with citrate as capping ligands. Their morphologies, structures, components, and photoluminescence properties were investigated and presented in this paper. A remarkable fluorescence enhancement up to 2.17 times was observed in colloidal YVO4:Eu/SiO2 NCs, compared to that of colloidal YVO4:Eu NCs. This is mainly attributed to the formation of the outer protecting layers of biocompatible SiO2 shells; which shield the Eu3+ ions effectively from water and thus reduces the deleterious effects of water on the luminescence. Meanwhile, on the basis of laser selective excitation, two kinds of luminescent centers were confirmed in the NCs, namely, inner Eu3+ ions and surface Eu3+ ions. The surface modifications for YVO4:Eu NCs effectively reduced the surface defects and accordingly enhanced the luminescence. The core/shell NCs exhibited long fluorescence lifetime and high photostability under ultraviolet radiation. 相似文献
14.
D.E. Wortman R.P. Leavitt C.A. Morrison 《Journal of Physics and Chemistry of Solids》1974,35(4):591-593
An analysis has been made of the optical spectrum of Tm3+ in YVO4 reported by K. D. Knoll. The approach taken was to describe the Tm3+ free ion as completely as possible and then to describe the effects of the crystal field on these levels. Parameters were obtained that gave an r.m.s. deviatioa of 10.6 cm?1 in a least squares fit. In Knolls' earlier analysis, which did not describe the free ion adequately, several sets of parameters were given that are consistent with different portions of the spectrum. The results computed with our parameters gave a new interpretation of the 3F4 and 3H5 multiplets and gave g∥ factors in good agreement with the measurements. The efiects of the hyperfine interaction and the spin-crystal field interaction on the energy levels resulted in displacements of smaller than 0.1 cm?1. 相似文献
15.
Hai-tao Huang Jing-liang He Xiu-wei Fan Yan Zhong Hong-liang Chai Yun Wang 《Optics & Laser Technology》2008,40(6):828-831
Q-switched mode locking (QML) has been observed in acousto-optic Q-switched Nd:YVO4 laser that contained no mode-locking components. It was found that QML was easily realized in a long cavity and the modulation depth was observed to increase with increased cavity length. The maximum modulation depth was as high as 90%. This phenomenon is explained by the introduction of gain-related effect in the gain medium. The longitudinal modes at higher frequency, than the central frequency of the gain profile, experience positive guiding, which results in mode locking of these modes. 相似文献
16.
Mei Yang Zheng Wen-Chen Yang Yu-Guang Liu Hong-Gang 《Physica B: Condensed Matter》2012,407(21):4365-4368
The g factors g∥ and g⊥ for the tetragonally-compressed (CrO4)3− clusters in YMO4 (M=V, P) crystals are calculated from the high-order perturbation formulas based on the two-mechanism model for the compressed d1 tetrahedra with the ground state |dz2〉. From the calculated values and by considering a small admixture of the first excited state |dx2−y2〉 to the ground state |dz2〉 due to the vibrational motion of ligands (which leads a twinkling compressed tetrahedron to become an elongated one), the observed g∥ and g⊥ for Cr5+ centers in YMO4 crystals are explained reasonably. The difficulty of the large deviations of g∥ from ge (≈2.0023) in the two systems is therefore removed and the above dynamic effect may be the cause which results in the large deviation of g∥ from ge for some (CrO4)3− clusters in crystals. 相似文献
17.
A passively mode-locked grown-together composite YVO 4 /Nd:YVO 4 crystal laser is demonstrated with a semiconductor saturable absorber mirror by 880-nm laser-diode direct pumping.Under the absorbed pump power of 24.9 W,a maximum output power of 10.5 W at the repetition rate of 77 MHz is obtained,corresponding to the optical-optical conversion efficiency of 42.1% and the slope efficiency of 53.4%.The pulse width measured is 33 ps at the output power of 10 W. 相似文献
18.
The thermal effects of the diode end-pumped Nd:YVO4 slab laser crystal are investigated both analytically and numerically. The theoretical model is established with considering the divergence of the pump beam in the slab. A detailed theoretical analysis of the temperature, stress and the focal length of thermal lens are presented. Using 3D finite element analysis, an accurate numerical solution based on the theoretical model is achieved. Our analysis includes the thermal fracture damage of the thermally and optically anisotropic slab and the predicated values are compared with the experimental results. 相似文献
19.
Hongrui Zhang Mingju Chao Mingyi Gao Liwen Zhang Jianquan Yao 《Optics & Laser Technology》2003,35(6):573-449
A fiber-coupled diode-single-end-pumped Nd:YVO4 laser with an Nd:YVO4 crystal of 0.3 at% doping concentration and 3×3×10 mm3 dimensions was reported. 14.850 W of continuous-wave output power in an M2 factor of 1.12 was obtained under pump power of 27.365 W, with an optical conversion efficiency of 60.49%, and a slope efficiency of 64.5%. 相似文献