高平均功率六棒串接脉冲Nd:YAG激光器

报道了一种腔内六棒串接的脉冲Nd:YAG激光器。采用44矩阵对晶体棒失调角度对谐振腔光轴的影响进行了理论分析,给出了六棒串接脉冲激光器中晶体棒失调角度的允许范围。在串接实验中,谐振腔采用对称平平腔结构,通过调整每根晶体棒的失调角度到允许范围内,实现了六棒串接脉冲Nd:YAG激光器。在输入电功率86 kW,占空比17%时,获得了平均功率3 018 W的脉冲激光输出,峰值功率17.75 kW,最高单脉冲能量为66 J,光束参数乘积为26.3 mmmrad,电光转换效率3.5%,长时间工作不稳定性小于2%。     

Einstein–Podolsky–Rosen entanglement in time-dependent broadband pumping frequency non-degenerate optical parametric amplifier

This paper investigates quantum fluctuations characteristic of time-dependent broadband pumping frequency non-degenerate optical parametric amplifier for below and above threshold regions. It finds that a high squeezing and entanglement can be achieved.     

Impact of Interacting Quantum Coherence via Decays and Incoherent Pumping on Transient and Steady-State Behaviors of Absorption

The effects from quantum coherence via decays and incoherent pumping on the lasing without inversion(LWI) are investigated in a four-level system.By analyzing the transient and steady-state behaviors of the absorption,we find that the gain occurs when both spontaneously generated coherence(SGC) and coherence induced by incoherent pumping(IPC) are considered.We attribute the occurrence of the gain to the interaction of quantum coherence via decays and incoherent pumping.     

Saturated X-ray lasing in Ni-like Sn at 11.9 nm using the GRIP scheme

We report on gain-saturated operation of the 11.9 nm X-ray lasing line in Ni-like Sn using the grazing-incidence pumping scheme (GRIP). The experiments were done with 2-ps duration pump pulses and energies up to 5 J. Strong gain saturation with multi-microjoule output was measured for the Sn laser at a grazing angle of 30° and a pump pulse energy of 3 J. This was achieved with a 4.5%, 2-ps duration prepulse 2.4 ns ahead of the main pulse and also incident at grazing incidence. Increasing laser output was observed at GRIP angles up to 45°. At this angle, the minimum energy required for saturated lasing was determined as ∼2 J.     

High-efficiency Nd:GdVO4 laser at 1341 nm under 880 nm diode laser pumping into the emitting level

Highly efficient 1341 nm continuous-wave laser under 880 nm diode laser pumping in Nd:GdVO₄ crystal is reported. Comparative results obtained by the traditional pumping at 808 nm were presented, showing that the slope efficiency and the threshold with respect to the absorbed pump power under 880 nm pumping was 34.9% higher and 12.6% lower than those of 808 nm pumping. A high slope efficiency of 49.1% was achieved under 880 nm pumping, with an optical-to-optical conversion efficiency of 41.7%.     

High-efficiency Nd:YVO4 laser emission under direct pumping at 880 nm

We report a high-efficiency Nd:YVO₄ laser pumped by an all-solid-state Q-switched Ti:Sapphire laser at 880 nm in this paper. Output power at 1064 nm with different-doped Nd:YVO₄ crystals of 0.4-, 1.0- and 3.0-at.% under the 880 nm pumping was measured, respectively. Comparative results obtained by the traditional pumping at 808 nm into the highly absorbing ⁴F_5/2 level were presented, showing that the slope efficiency and the threshold with respect to the absorbed pump power of the 1.0-at.% Nd:YVO₄ laser under the 880 nm pumping was 17.5% higher and 11.5% lower than those of 808 nm pumping. In a 4-mm-thick, 1.0-at.% Nd:YVO₄ crystal, a high slope efficiency of 75% was achieved under the 880 nm pumping, with an optical-to-optical conversion efficiency of 52.4%.     

不同脉冲重复频率下抽运方式对全光纤声光调Q激光器性能的影响

在不同初始边界条件下数值求解描述全光纤声光调Q双包层光纤激光器的速率方程,得到前向抽运结构和后向抽运结构下激光器上能级粒子数在增益光纤中的分布,以及脉冲能量、平均功率、脉宽、光纤中储能与脉冲重复频率、抽运合束器对信号光透过率、抽运功率的相互关系.从谐振腔内放大自发辐射光的产生影响谐振腔损耗的角度分析仿真结果,并实验验证两种抽运方式对输出脉冲功率和脉冲宽度的影响.结果表明：不同脉冲重复频率下抽运方式会对全光纤声光调Q激光器性能产生显著影响,为获得较好的脉冲输出性能,在重复频率较低 关键词： 光纤激光器 Q')" href="#">声光调Q 抽运方式     

不可逆三源化学势变换器性能的优化分析

建立受传质和质量漏不可逆性影响的一类三源化学势变换器的新循环模型,分析这些不可逆性对化学势变换器性能的影响,导出性能系数与泵能率间的基本优化关系和其它参数的优化表式,同时确定了化学势变换器一些重要参数的最佳工作区域和性能界限。     

基于物联网的一体化泵站设计与实现

针对传统泵站的计费模式单一、操作复杂、管理困难等问题,采用物联网思想设计并实现了一种一体化泵站系统。感知层采用STM32F407单片机,基于mbed-rtos操作系统对不同类型的传感器进行数据采集并对软启动器、摄像头进行控制,网络层利用MQTT通信协议将数据发送到云计算中心服务器,应用层通过手机客户端或网页登陆泵站管理系统实现泵站用水数据的实时查看、泵站监控等功能。系统运行稳定可靠,能够较传统泵站更好的完成计费抽水等任务,为泵站的自动化提供了一种可靠的一体化解决方案。     

采用超导量子干涉组件在微特斯拉磁场下获取超极化~3He的核磁共振波谱和影像(英文)

该文以超导量子干涉元件研究光激发氦三极化气体的低磁场磁共振与造影术.使用圆偏极化雷色光将氦三气体极化,超导量子干涉元件磁共振与造影之测量是以磁通耦合方式来进行,超导量子干涉元件是用铋锶钙铜氧高溫超导罐来隔离环境噪音.此方法测得的磁共振信号与影像相较于直接将样品置于杜瓦瓶下方有较高的信噪比,当样品无法靠近感测元件时,此装置具高信噪比特色.磁通耦合方式的超导量子干涉元件低磁场磁共振与造影术及其氦三极化气体的肺部造影在学术与应用上是相当有趣.