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1.
基于提出的能量均分方法,理论分析和系统模拟了大功率激光二极管(LD)端面抽运Nd:YAG激光陶瓷板条阶变梯度浓度掺杂情况下板条温度分布及应力分布情况.采用板条阶变梯度浓度掺杂结构,在抽运效率很高的情况下,抽运吸收光功率分布更加均匀,产生更小的热应力,从而解决抽运效率和抽运吸收功率均匀性之间的矛盾.  相似文献   

2.
刘全喜  任钢  李轶国  岳通  王莉  肖星  邓翠  李佳玲 《红外与激光工程》2019,48(11):1105004-1105004(11)
基于能量均分方法,根据经典热传导和热弹性理论,建立了激光二极管端面抽运梯度浓度掺杂棒状激光介质的数值模型,考虑到梯度浓度掺杂激光介质端面与空气的对流换热和激光介质材料的热力学参数的温度相关性,运用有限元法,得出了单一浓度掺杂、2阶阶变梯度浓度掺杂、5阶阶变梯度浓度掺杂和理想梯度浓度掺杂四种掺杂结构激光介质内吸收系数、抽运光吸收功率、温度、热应力和应变的空间分布。结果表明,采用梯度浓度掺杂结构可以大大提高激光介质内抽运光吸收分布的均匀性,5阶阶变梯度浓度掺杂激光介质的最高温度、最大主拉应力和最大主应变分别为单一浓度掺杂激光介质的42.6%、31.9%和28.1%,可见明显减小了热效应的影响。理论分析结果可为激光二极管抽运梯度浓度掺杂激光器的合理优化设计提供数据理论支撑。  相似文献   

3.
为研制高功率的板条功率放大模块,对Nd∶YAG板条激光器的增益介质的热结构进行了研究。采用有限元方法仿真了高功率激光二极管阵列端面抽运Nd∶YAG板条介质的温度、应力分布,数值模型考虑了抽运光在介质内的不均匀分布。结果表明,板条介质掺杂和未掺杂结合部位温度和应力最高,是整个板条介质的薄弱环节,应优化设计避免板条破裂。以此为参考设计高功率放大模块,而后搭建激光放大链路,种子光功率2.5 W,通过一级预放模块四程放大后,再经过四级功放模块双程放大,实现了11 kW激光输出。实验中测量了高功率抽运条件下增益介质的温度分布,与数值仿真结果基本符合。  相似文献   

4.
LD侧面抽运的Nd∶YAG激光器抽运均匀性研究   总被引:2,自引:0,他引:2  
通过对激光二极管 (LD)侧面抽运激光介质的分析研究 ,建立了二极管侧面抽运激光介质所吸收的抽运光功率分布的数学模型。采用光线追迹法模拟计算出单个二极管在不同抽运参数下直接抽运激光棒时 ,激光棒所吸收的抽运光功率的分布。比较了介质的吸收系数和二极管到激光棒距离的不同给抽运的均匀性带来的差异。计算了在有冷却系统的条件下 ,多个二极管阵列抽运时的抽运光功率分布 ,得到了较好的抽运均匀性  相似文献   

5.
LD侧面抽运的Nd:YAG激光器抽运均匀性研究   总被引:10,自引:4,他引:6  
通过对激光二极管(LD)侧面抽运激光介质的分析研究,建立了二极管侧面抽运激光介质所吸收的抽运光功率分布的数学模型。采用光线追迹法模拟计算出单个二极管在不同抽运参数下直接抽运激光棒时,激光棒所吸收的抽运光功率的分布。比较了介质的吸收系数和二极管到激光棒距离的不同给抽运的均匀性带来的差异。计算了在有冷却系统的条件下,多个二极管阵列抽运时的抽运光功率分布,得到了较好的抽运均匀性。  相似文献   

6.
LD侧边抽运板条激光器的热效应   总被引:1,自引:1,他引:0  
对LD侧边抽运的板条激光介质热效应进行理论分析与数值模拟,根据2.5 mm×14 mm×40 mm Nd∶YAG板条实物建立了相应的三维(3D)热模型,采用有限元方法分析并模拟了板条激光介质内部温度场和热应力的分布,给出在120 W抽运功率下板条激光介质的热畸变特性,估算了在不同抽运功率下热焦距的大小.在此基础上设计并封装了LD侧边抽运的板条激光模块,对该模块的热焦距进行实验研究,得到热焦距随抽运功率变化的测量曲线,实验结果与理论分析一致.  相似文献   

7.
提出了定量表征激光棒内吸收抽运光分布均匀性特征参量--吸收抽运光分布均方根偏差相对值,利用该参量以及自行编制的光线追迹程序,定量分析了五向侧面抽运Nd:YAG模块内吸收抽运光分布均匀性及耦合吸收效率随激光二极管(LD)Bar条与Nd:YAG棒表面间距的变化规律,确定了侧面抽运模块优化结构参数;在此基础上研制了抽运频率为100 Hz,占空比为2%的侧面抽运Nd:YAG模块,其808 nm最大平均抽运功率为200 W,1064 nm短腔最大输出功率为95 w,光-光转换效率为47.5%.  相似文献   

8.
高功率二极管角抽运Yb:YAG板条激光器   总被引:1,自引:0,他引:1  
报导了一种用于高功率固体激光器的新型抽运方法——角抽运方法,抽运光从板条激光器结构中的板条工作介质的角注入,具有抽运均匀、抽运功率密度高、可扩展性强等优点,利用该抽运方法,获得了连续功率1016W的输出,斜效率42.8%,光-光转换效率33.6%。  相似文献   

9.
端面抽运复合结构板条介质热效应分析   总被引:1,自引:0,他引:1  
通过对激光二极管端面抽运板条介质工作特点的分析,从热传导方程出发,对端面抽运、传导冷却的板条介质的温度场和热应力进行了理论计算.然后,基于LAS-CAD软件的有限元分析(FEA),分别对单一板条和复合板条的温度场和热应力分布进行了数值模拟.通过模拟结果可知,采用复合结构板条介质不仅大幅降低了晶体的温度值,减小了温度分布...  相似文献   

10.
V型有源镜构型热容激光器热特性研究   总被引:1,自引:1,他引:0  
为了提高抽运效率、改善抽运均匀性、克服热退偏的影响,建立了一套V型有源镜构型热容激光器,采用数值模拟与实验研究相结合的方法,对激光介质热分布进行了研究。数值模拟充分考虑了内热源的分布不均匀性,分析了激光介质的3维热分布。实验中采用热像仪对激光介质的表面温度进行了无接触测量。数值计算和实验研究结果具有较高的一致性。研究结果表明,该激光器构型对于提高热分布均匀性有较大的帮助。  相似文献   

11.
为了分析角部抽运方式在中小功率激光器设计中的可行性,基于光线追迹法,计算了不同的激光介质几何结构参量和不同的二极管温度条件下角部抽运复合板条激光器的抽运效率和抽运均匀性。从模拟计算结果可知,只要选择合理的激光介质结构参量,角抽运方式能得到高的抽运效率和较好的抽运均匀性。设计了一种角部抽运Nd:YAG复合板条激光器,在45W的抽运功率下获得了12W的激光输出,光光转换效率约为26.7%,在40W抽运时光束质量Mx2=1.47,My2=1.36。理论分析和实验设计表明,角抽运方式在小功率激光器设计中是可行的。  相似文献   

12.
为了实现薄片激光器高吸收转换效率的目的,采用多次抽运吸收的方式,结合光斑离轴非对称反射抛物面和光斑对称分布非球面的抽运结构,提出了一种可以提高非球面光束分布占空比的高冲程抽运的新方法。设计了多种不同抽运冲程的结构,使用ZEMAX模拟验证了24冲程抽运时的光路分布和光斑位置图,通过比尔吸收定律理论计算了不同抽运冲程下薄片晶体对抽运光的吸收效率。结果表明,所设计的24冲程、36冲程、40冲程和80冲程的抽运结构,其中36冲程的吸收效率的性价比最高。该研究对高功率、高冲程、小体积的抽运结构设计具有指导作用。  相似文献   

13.
We propose a new geometry of a clad-pumped fiber amplifier/laser that includes at least one doped core which guides the signal wave and at least one clad region that guides the incoherent pump. Our proposed geometry enables the incoherent diode pump light to be efficiently absorbed by the doped glass core over very short lengths on the order of a few to tens of centimeters. The transparent cladding is realized as a narrow slab with refractive index higher than that of the core. The slab is designed to effectively capture all of the incoherent pump light and is tapered to force the highly moded incoherent guided light into the strongly absorbing core. Modes of this composite waveguide structure are analyzed. Criteria are established in terms of the refractive indices of the core, slab, and cladding that ensure efficient absorption of the pump light in the core while ensuring that only a single or few lowest order signal modes can propagate in the amplifying core. Numerical simulations with the beam propagation method and a modal expansion technique confirm that a significant enhancement of the absorption efficiency of the pump in the core can be realized by tapering the slab waveguide. Assuming a local absorption rate of 10 m/sup -1/ of the intensity of the pump in a core of radius 4.3 /spl mu/m and a realistic multimode diode pump distributed over a 100-/spl mu/m aperture, an absorption efficiency of 94% can be realized over an amplifier length of 2 cm. The geometry is scalable to longer lengths and multiple incoherent diode-pumped slab claddings.  相似文献   

14.
A new and simple method of pumping short high-power optical fiber lasers and amplifiers is described. In our approach, several passive coreless optical fibers are brought into direct contact alongside a single rare-earth doped active fiber which constitutes the active medium of the laser (amplifier). Pump light is delivered through the passive coreless fibers and penetrates into the active fiber via evanescent field coupling. To enhance the pump absorption in the gain medium, high-order spatial modes are excited in the pump delivery fibers, and an active fiber with high concentration of the dopant ions is used. As a demonstration of the viability of our approach, test results are reported on a 12-cm-long Er/sup +3/-Yb/sup +3/ codoped phosphate glass fiber laser. The laser output reaches 5 W using 23-W pumping into six coreless fibers. Above threshold, the laser has /spl sim/24% optical-to-optical conversion efficiency (with /spl sim/64% being the theoretical maximum). The linearity of the input-output characteristic for the laser suggests that the output power can be scaled up by applying higher pump power.  相似文献   

15.
The authors report efficient pulse operation of an Nd:glass slab laser-side-pumped by laser diode arrays. 7.5 mJ output and a slope efficiency of 29% were obtained with 35 nJ pump energy at 0.8 μm in 200 μs pulses. The wide absorption band at 0.8 and low laser loss in this phosphate glass allow for efficient pump light absorption and straightforward scalability to high power. The authors demonstrate 22% optical efficiency in a long pulse, multimode diode pumped laser oscillator based on a phosphate laser glass, LHG-8, highly doped with Nd 2O3. The strong and wide absorption bands in such phosphate glasses allow efficient pumping while somewhat relaxing the expensive wavelength selection requirements for laser arrays compared with crystal line host materials. With such materials, smaller slab thickness or rod diameters that are feasible with Nd:YAG can be used in the side-pumping geometry  相似文献   

16.
We describe erbium-ytterbium co-doped fiber lasers in different free-running and tunable configurations. The lasers were cladding-pumped by high-power multimode diode sources. We compare pumping at 915 and 980 nm. With a free-running laser, we obtained slope efficiencies of up to 50% with 915-nm pumping and 38% with 980-nm pumping, with respect to absorbed pump power. We reached a double-ended output power of 16.8 W from the free-running laser. Thanks to a high rare-earth concentration and a small inner cladding area (possible with the high-brightness pump sources we used), the operating pump absorption of the fiber reached 8 dB/m. With such high absorption, short fibers with high nonlinear thresholds are possible even with cladding pumping. The tunable fiber laser had a tuning range from 1533 to 1600 nm and emitted 6.7 W of output power at 1550nm in a high-brightness, single-polarization, narrow linewidth beam.  相似文献   

17.
设计了3类8种二极管侧面泵浦结构,构建了相应的泵浦光学理论模型,采用有限元分析方法,计算了不同结构下的吸收效率和矩阵元素标准差。首先,在给定泵浦总功率、芯片间距、掺杂浓度等前提下,随着泵浦距离在0~5 mm内递增,8种泵浦结构中激光晶体的吸收效率呈降低趋势,矩阵元素标准差也逐渐减小,其中部分结构在近距离(0~0.3 mm)泵浦时矩阵元素标准差变化程度较大,在实际应用中应避免泵浦距离处于近距离区间。其次,在相同结构参量下,随着晶体掺杂浓度在0.6%~1.0%内增加,激光晶体的吸收效率提高,同时,掺杂浓度提升也是造成截面中心峰值降低或半径方向上光场凹陷的原因。因此,掺杂浓度和泵浦距离的匹配将是提升半径方向上均匀性分布的有效手段。  相似文献   

18.
The properties of a coplanar-pumped folded-slab laser under the influence of thermal lensing have been modeled and measured. It is shown that despite the formation of a strong astigmatic lens within the slab, the results can be used to design resonators capable of good TEM00 performance, suitable for a wide variety of applications. Good agreement is found between modeling and measurement of slab and laser parameters. Using a novel technique, the fraction of absorbed pump power converted to heat has been measured under diode-laser pumping  相似文献   

19.
Theoretical results relating to the generation of continuous-wave (CW) output from fiber lasers that are internally pumped with light generated from the stimulated Raman effect are presented. This investigation establishes the important fiber and resonator parameters, such as the fiber length and glass composition, dopant concentration, and pump power required to realize this new form of fiber laser arrangement. Three examples are studied: the Ho3+-doped silica fiber laser that is pumped at a wavelength of 1.15 μm, the Er 3+-doped silica fiber laser which is pumped at 1.48 μm and, the Tm3+-doped silica fiber laser which Is pumped at 1.625 μm. These three examples cover first Stokes pumping, second Stokes pumping, and first Stokes pumping with direct dopant absorption of the pump light, respectively. The simulations involve the use of simple numerical models comprising the spatially dependent field propagation equations (under the slowly varying field approximation) and the rate equations for the population densities. It is established that intracavity Raman pumping of fiber lasers with first Stokes radiation is efficient when the losses at the pump, Stokes and laser wavelengths are kept low (<10 dB/km). It is also established that second Stokes pumping is, even with direct absorption of the pump light, theoretically quite efficient and, as a result, the Er3+-doped silica fiber laser which is pumped with second Stokes radiation at 1.48 μm may provide the best demonstration of intracavity Raman pumping  相似文献   

20.
采用平板几何金属衬底模型对雷达波在均匀等离子体中传播所发生的吸收、反射和衰减进行了数值分析研究,结果表明:等离子体对电磁波的吸收衰减取决于等离子体密度和碰撞频率的共同作用;通过适当选择等离子体密度和等离子体碰撞频率,可以使均匀等离子体对某一雷达波段的吸收达到90%以上,隐身效果显著。  相似文献   

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