共查询到19条相似文献,搜索用时 109 毫秒
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采用氙灯泵浦新型晶体Nd:Sr5(PO4)3F,以KTP晶体腔内倍频,实现了该晶体0.5295μm绿光激光BDN染料片调Q运转。测量了输出绿光激光的特性及不同腔长和染料片小信号透过率情况下的输出能量及脉冲宽度,给出了染料片调Q腔内倍频的耦合波方程组,数值求解该方程组,所得的理论数据与实验结果较好地相符。 相似文献
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LD抽运的折叠腔Nd∶YVO4/KTP倍频红光激光器 总被引:1,自引:0,他引:1
对LD端面抽运的Nd∶YVO4/KTP腔内倍频激光器的三镜折叠腔结构进行优化设计,研究了总腔长、输入镜曲率半径和Nd∶YVO4和KTP晶体的热效应对激光谐振腔的稳定区域、Nd∶YVO4晶体内基模光束半径的影响。实验结果表明:该方法所得出的结论与理论相吻合。在实验中比较了折叠腔不同折叠角度的红光输出功率,并获得了最佳折叠角度为25°,其有效倍频效率为10.8%。最后使用基频光的偏振特性与KTP的相位匹配之间的关系对实验结果进行理论解释。 相似文献
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本文利用Auger分析技术和C-V测量方法,详细地研究了PECVDSi3N4/InP界面特性,Auger能谱分析表明热处理使界面面发生互扩散,同时InP的热分解导致P元素穿过Si3N4薄膜到达表面。C-V测量表明Ag/Si3N4/InPMIS结构可以实现载流子的堆积、耗尽和反型。 相似文献
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端面泵浦双Nd: YVO4激光器中热效应对腔稳定性的影响 总被引:7,自引:6,他引:1
利用多个激光晶体串接方式可以提高固体激光器的输出功率. 发展双Nd: YVO4晶体激光器, 将晶体的端面镀膜作为谐振腔的端面镜, 构成了平行平面谐振腔. 对平行平面谐振腔的等效腔进行了理论分析, 结果表明激光晶体吸收泵浦光产生的热透镜效应对保持腔的稳定性起到了重要的作用. 在国内首次进行了双端泵浦双Nd: YVO4激光器的实验研究, 在抽运功率为 20.74 W时获得了11 W的1064 nm TEM00模激光输出, 其光-光转化效率约为53%. 并且对于不同掺杂浓度下的实验结果进行了讨论. 相似文献
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两参数变形量子代数SU(1,1)q,s的相干态及其性质 总被引:1,自引:1,他引:0
利用SU(1,1)q,s量子代数的两参数变形振子构造出归一化的SU(1,1)q,s相干态,证明了SU(1,1)q,s量子代数的表示基是正交的,并讨论了它的相干态的归一性和完备性。指出(SU(1,1)q,s相干态的相干性受参数q、s的影响。 相似文献
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借助一个满足量子Heisenberg-Weyl代数(H-Wq,s代数)的多模算符,给出了量子代数SU(2)q,s和SU(1,1)q,s的k(k≥2)模实现,并构造了相应的相干态. 相似文献
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测量了 Nd:S-VAP[Nd:Sr5(VO4)3F]晶体的吸收光谱特性,在583.0nm 和809.0nm处有强烈的吸收峰.用可调谐染料激光泵浦实现了低阈值、高效率的激光运转.在透射率15%的平-平腔情况下,斜率效率为50%,阈值2mJ,倍频绿光的中心波长为536.0nm,线宽为1.4nm.采用φ4mm×30mm 的氙灯泵浦,实现了自由运转和染料片调 Q 运转.阈值为130mJ,斜效率为1.3%.测量了不同腔长、不同染料片小信号透射率情况下的输出能量、脉冲宽度以及光束发散角和偏振特性等. 相似文献
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We present a comparison between intracavity cooling and external cavity cooling for optical refrigeration. The results show that the intracavity scheme is preferred at low optical densities (〈 0.008), while the external cavity scheme is preferred at higher optical densities (〉 0.01). We can choose the proper scheme for different eases in experiments. Moreover, under the same conditions, taking Yb^3+-doped ZBLAN (ZrF4-BaF2-LaF3-AlFa-NaF) film as an example, the cooling processes of the two scheme are obtained. The calculated results show that intracavity cooling will achieve a larger temperature drop for a thin film sample. Finally, the diode laser may become a candidate for the intraeavity model briefly discussed. 相似文献
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k光子Jaynes-Cummings模型的亚Poisson光子统计特性研究 总被引:9,自引:4,他引:5
本文利用量子电动力学理论,首次对 k 光子 Jaynes-Cummings 模型中单模激光场的稳态亚 Poisson 光子统计性质进行了系统研究.结果表明:在一般情况下,激光上能级相对泵浦参量 xa 具有一个确定的阈值 xat;当 xa>xat时,光场呈现亚 Poisson 光子统计;当 xa>>xat时,光场呈现出深度且完全恒定的亚 Poisson 光子统计.在特殊情况下,阈值 xat-0,这时在激光腔内将直接诱发亚 Poisson 光子统计.随着 k(k≥2)值增加,阈值 xat降低,光场亚 Poisson 光子统计程度增强. 相似文献
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CAO Ning LI Qi-Nan ZHAO Yan-Ying XU Chang-Wen WEI Zhi-Yi FENG Bao-Hua ZHANG Zhi-Guo ZHANG Huai-Jin WANG Ji-Yang HE Kun-Na GAO Chun-Qing 《中国物理快报》2008,25(11):4016-4018
We report an efficient pumping scheme which involves a direct excitation of the upper lasing level of a four-level laser in a Nd-doped Ca3(NbGa)2-xGa3O12 (Nd:CNGG) by using a tunable Ti:sapphire, 700-920nm, cw pump source. The slope efficiency is improved from 10.5% of the traditional band pumping at 808nm to 21.8% of the direct pumping at 882nm. The influence of pumping wavelength on lasing is discussed. We present a scheme of double pumping for lasing. 相似文献
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Laser-induced etching of polycrystalline Al2O3TiC material by a tightly-focused cw Ar ion laser has been investigated in a KOH solution with different concentrations. It is found that the KOH concentration can strongly affect the etching quality where low KOH concentration can result in rough and irregular patterns. Laser-induced etching of polycrystalline Al2O3TiC in a KOH solution is found to be a photothermal reaction in which a threshold laser power exists. With an appropriate set of etching parameters, well-defined grooves can be obtained with clean side walls and with an etching rate up to several hundred micrometers per second. The etching behavior is also found to depend on laser scanning direction. It is also found that the grains in the polycrystalline Al2O3TiC material play an important role in the etching dynamics and etching quality. This etching process is believed to be applicable to the formation of a slider surface of magnetic heads in the future. 相似文献
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J. Zhang K. Sugioka T. Takahashi K. Toyoda K. Midorikawa 《Applied Physics A: Materials Science & Processing》2000,71(1):23-26
A new technique of dual-beam laser ablation of fused silica by multiwavelength excitation process using a 248-nm KrF excimer laser (ablation beam) coupled with a 157-nm F2 laser (excitation beam) in dry nitrogen atmosphere is reported. The dual-beam laser ablation greatly reduced debris deposition and, thus, significantly improved the ablation quality compared with single-beam ablation of the KrF laser. High-quality ablation can be achieved at the delay times of KrF excimer laser irradiation shorter than 10 ns due to a large excited-state absorption. The ablation rate can reach up to 80 nm/pulse at the fluence of 4.0 J/cm2 for the 248-nm laser and 60 mJ/cm2 for the F2 laser. The ablation threshold and effective absorption coefficient of KrF excimer laser are estimated to be 1.4 J/cm2 and 1.2᎒5 cm-1, respectively. 相似文献
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We report that a deep ultraviolet (DUV) laser from the sixth harmonic of a 1064nm laser has been firstly used as light source in an ultrahigh energy-resolution angle-resolved photoemission spectroscopy (ARPES). The wavelength is 177.3nm obtained by using the second harmonic KBe2BO3F2 crystal with a frequency tripled 1064nm Nd:YVO4 laser. The large flux (10^14 - 10^15 photons/s) and narrow line width (0.26 meV) are suitable for the ultrahigh-energy resolution ARPES. The laser-ARPES can be a powerful tool to study the electronic structure at and near the Fermi level of the superconductor and correlated materials. The laser-ARPES has worked more than 500 h already. 相似文献
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Near-infrared luminescence is observed from bismuth-doped GeS2-Ga2Sa chalcogenide glasses excited by an 808 nm laser diode. The emission peak with a maximum at about 1260 nm is observed in 80GeS2-2OGa2 Sa:O.fBi glass and it shifts toward the long wavelength with the addition of Bi gradually. The full width of half maximum (FWHM) is about 200 nm. The broadband infrared luminescence of Bi-doped GeS2-Ga2Sa chalcogenide glasses may be predominantly originated from the low valence state of Bi, such as Bi+. Raman scattering is also conducted to claxify the structure of glasses. These Bi-doped GeS2 Ga2Sa chalcogenide glasses can be applied potentially in novel broadband optical fibre amplifiers and broadly tunable laser in optical communication system. 相似文献
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A.M. Malyarevich K.V. Yumashev N.N. Posnov V.P. Mikhailov V.S. Gurin 《Applied physics. B, Lasers and optics》2000,70(1):111-116
Nonlinear optical properties of surface-oxidized CuFexSy (x=1, 2, y=2, 3) nanoparticles incorporated in polymeric film are studied. Surface oxidation of CuFeS2 and CuFe2S3 nanoparticles results in appearance of the additional absorption band with maximum at 1.03 and 1.15 7m, respectively. Bleaching of this additional absorption band in CuFe2S3 particles and the induced absorption in all studied samples after picosecond laser excitation take place. An energy level scheme for CuFeS2 and CuFe2S3 nanoparticles with long-lived trap levels in the band gap is proposed and the origin of additional absorption is discussed. Characteristic times for career relaxation from conduction band to these trap levels are ᅉLJ ps for CuFe2S3 and ᅶᆞ ps for CuFeS2 oxidized nanoparticles. The relaxation of electrons from trap levels has a characteristic time of more than 500 ps. 相似文献