共查询到18条相似文献,搜索用时 187 毫秒
1.
在固体激光腔运行中热透镜的屈光度,1ft,作为谐振腔的动力学因子,对腔的运行特性有着关键性的影响作用.运用变换圆图解方法,对固体激光腔的光模特性的动力学稳定性作了详细的分析,给出了它对动力学因子及腔参数u1=L1(L1-R1)R1与u2=L2(L2-R2)R2的依赖关系.给出了腔参数u1与u2的直观物理图像描述;在此基础上,利用变换圆图解方法,进一步讨论,如何选择腔参数u1与u2,调节稳定区内运行的最小基模光斑尺寸和动力学稳定区的宽度,及调控动力学稳定区的‘位置’;提出了两倍拓宽动力学稳定区的一个可行方案;最后,还讨论了动力学敏感腔的存在及其在自调Q激光器与自Kerr透镜锁模激光器中的可能运用.
关键词:
固体激光器
热透镜
动力学稳定性的调控 相似文献
2.
为了获得大功率高亮度的激光光源,设计并实现了一种使用双棒串接的基模动态稳定谐振腔.通过补偿热致双折射效应以及合理地设计腔内参数,在使用闪光灯抽运的条件下获得了61W的基模连续输出.使用等效热透镜的方法分析了谐振腔参数对激光器性能的影响,解释了输出镜和全反镜的距离对激光器性能所起的不同作用.
关键词:
动态稳定腔
双棒
谐振腔模式 相似文献
3.
4.
5.
本文发展了变换圆图解处理方法,并运用它求得了热不敏感腔的一般解:σ1圆与πf圆相切,清晰地阐明了它的主要特征;同时,澄清了有关它的特证的若干不确切的看法,进而,还求得了最佳热不敏感腔的特别解:g1*g2*=1/2;L2=0或L2=R2。
关键词: 相似文献
6.
高光学质量,高平均功率非稳腔Nd:YAG激光器 总被引:1,自引:0,他引:1
在分析含热透镜的非稳腔固体激光器普遍特性的基础上,分别定义了几何放大率和输出曲率半径的热敏感度,结合腔镜失调敏感度而成为设计该类谐振腔的重要依据,据此,进一步改善和发展的新型的棒成像非稳腔。 相似文献
7.
8.
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%。 相似文献
9.
10.
《光学学报》2010,(8)
在高功率激光二极管(LD)抽运条件下,固体增益介质的热透镜效应是优化激光谐振腔系统所必须考虑的重要因素之一。利用带尾纤耦合输出的激光二极管和整形聚焦透镜组组合抽运Nd:YVO4晶体,用稳腔法测量了激光晶体的等效热焦距。利用LAS-CAD软件模拟了三种热稳腔结构在所测等效热焦距下的模式分布,对LD双端抽运Nd:YVO4激光器Z字型谐振腔进行优化设计后,实验选定后腔镜曲率半径R1=300mm,输出镜曲率半径R2=100mm,腔长Ltotal=280mm,耦合输出镜透射率T=50%。当输入61W抽运功率时,激光最高输出功率达21.3W,光束质量因子M21.41,所得激光器输出结果与理论预期吻合得很好。 相似文献
11.
Various criteria for designing high power convective cooled CO2 lasers have been discussed. Considering the saturation intensity, optical damage threshold of the optical resonator components
and the small-signal gain, the scaling laws for designing high power CW CO2 lasers have been established. In transverse flow CO2 lasers having discharge of square cross-section, the discharge lengthL and its widthW for a specific laser powerP (Watt) and gas flow velocityV (cm/s) can be given byL = 1.4 x 104
p
1/2
V
-1 cms andW = 0.04P
1/2 cms.
The optimum transmitivity of the output coupler is found to be almost constant (about 60%), independent of the small signal
gain and laser power. In fast axial flow CO2 lasers the gas flow should be divided into several discharge tubes to maintain the flow velocity within sonic limit. The
discharge length in this type of laser does not depend explicitly on the laser power, instead it depends on the input power
density in the discharge and the gas flow velocity. Various considerations for ensuring better laser beam quality are also
discussed. 相似文献
12.
V. P. Strakhov 《Journal of Experimental and Theoretical Physics》2003,96(6):1122-1123
The emission spectrum of an injection GaAs laser with a four-sided resonator with a square cross section of size 13×13 μm2 is presented. This laser is the world’s smallest laser, having the threshold current Ith=0.7 mA and a photon flight time in the resonator that is shorter than the thermal relaxation time T2. It is shown that the emission spectrum of the laser drastically differs from the spectrum emitted by lasers of usual size. 相似文献
13.
14.
A relation between the far field divergence angle of a laser output beam and the elements of the laser resonator matrix is derived. This relation is applied to the resonator matrix of directly coated laser rods and yields an expression for the far field angle θm of the output beam in terms of the pump light induced refractive power D of the rod. By means of this expression D versus the average pumping power is calculated from the experimental values of θm for several laser rods and is found to be in good agreement with previously published values. 相似文献
15.
M. Stanislawki J. Meister T. Mitra M.M. Ivanenko K. Zanger P. Hering 《Applied physics. B, Lasers and optics》2001,72(1):115-120
The Er:YAG and the CO2 laser are competitors in the field of hard tissue ablation. The use of Er:YAG lasers (2.94 μm, pulse length
L of 100 to 200 μs) show smaller areas of thermal defects then ‘‘superpulsed’’ CO2 lasers with pulse lengths of approximately 100 μs. Only the development of a Q-switched CO2 laser (9.6 μm, τL=250 ns) allowed for similar results. In this paper new results for the Er:YAG and the Q-switched CO2 laser under the influence of water spray will be presented. Several parameters are of special interest for these investigations:
the specific ablation energy, which shows a minimum for the CO2 laser at an energy density of 9 J/cm 2 and a broad shallow minimum in the range of 10 to 70 J/cm2 for the Er:YAG laser, and comparison of the cut-shape and depth. Surface effects and cutting velocity are discussed based
on SEM pictures.
Received: 19 July 2000 / Revised version: 1 November 2000 / Published online: 30 November 2000 相似文献
16.
R. Occelli J. M. Moynault O. Bachet R. Coulon 《International Journal of Infrared and Millimeter Waves》1985,6(4):269-286
In order to develop a coherent optical source intended for very low frequency laser spectroscopy, we have studied, manufactured and then tested (calibrated) a device for generating submillimetric waves by frequency difference in a non linear crystal.The mounting is made of two single mode and single line T E A CO2 lasers which, by means of an AsGa crystal, allows the difference f3=f1–f2 of the two near frequencies f1 and f2 emitted by each laser to be obtained.We present a system using two CO2 atmospheric lasers with a simple and efficient pre-ionization and an original treatment of the electrodes.Manufacturing characteristics of the primary sources are detailed and then the obtained Far Infra Red (F I R) emission is studied. 相似文献
17.
Lasers for materials processing: specifications and trends 总被引:2,自引:0,他引:2
K. Du J. Biesenbach D. Ehrlichmann U. Habich U. Jarosch J. Klein P. Loosen J. Niehoff R. Wester 《Optical and Quantum Electronics》1995,27(12):1089-1102
An overview is given of the types of lasers dominating the field of laser materials processing. The most prominent lasers in this field are the CO2 and the Nd: YAG laser. The domain of CO2 lasers is applications which demand high laser powers (up to 30 kW are available at present), whereas the domain of Nd:YAG lasers is micro-machining applications. In the kilowatt range of laser output power, the two types of lasers are in competition. New diffusion-cooled CO2 laser systems are capable of output laser powers of several kilowatts, with good beam qualities, while still being quite compact. The output power and beam quality of Nd:YAG lasers has been improved in recent years, so that Nd:YAG lasers are now an alternative to CO2 lasers even in the kilowatt range. This is especially true for applications that demand optical fibre transmission of the laser beam, which is possible with Nd:YAG laser light but not with the longerwavelength light emitted by CO2 lasers. The main problem in solid-state lasers such as Nd:YAG is the thermal lensing effect and damage due to thermal stresses. In order to reduce thermal loading, cooling has to be enhanced. Several alternative geometries have been proposed to reduce thermal loading and, by this, thermal lensing effects. There are now slab and tube geometries which allow much higher output powers than the conventionally used laser rods. A very new scheme proposes a thin slab whose cooled side is also used as one of the laser mirrors, so that thermal gradients occur mainly in the direction of the beam propagation and not perpendicular to it, as is the case in the other geometries. As well as CO2 and Nd:YAG lasers, semiconductor laser diodes are very promising for direct use of the emitted light or as pump sources for Nd:YAG and other solid-state lasers. When packaging together thousands of single laser diodes, output powers of several kilowatts can be realized. Major problems are collimation of the highly divergent laser beams and cooling of the laser diode bars. 相似文献
18.
This paper presents a first comprehensive study on the pointing stability of copper vapor laser with an emphasis on bringing out the role of optical resonator. Long term (∼10 min), single pulse, far-field beam pointing stability of a 5.5 kHz repetition rate copper vapor laser (λ = 510 nm) with plane-plane, unstable and filtering resonators, is studied. It is established that the resonator optics largely decides the CVL pointing stability. Minimum beam pointing angle of 8 μrad from generalized diffraction filtered resonator (GDFR) is obtained in contrast to a maximum value of 120 μrad from the plane-plane resonator. The unstable resonators data is in between. The relative trends in CVL pointing stability are discussed in terms of wave-front distortions due to resonator mode build up from optical noise, thermal and mirror misalignment effects. The degree of optical resonator immunity to phase distortions dictates the net pointing stability achieved. 相似文献