Yb:YAG power oscillator with high brightness and linear polarization

A diode-pumped Yb:YAG laser with a novel end-pumped zigzag slab architecture has been developed. This architecture provides uniform transverse pump profiles, conduction cooling of the laser crystal, mechanical robustness, and ready scalability to higher powers. At room temperature the laser emits 415 W of cw power with 30% optical conversion efficiency. An image-inverting stable resonator permits a high-brightness output of 252 W with linear polarization and an average M(2) beam quality of 1.45. Q-switched pulse energies of as much as 20 mJ and average Q-switched powers of as much as 150 W were obtained while M(2) was maintained at <1.5.     

Yb:YAG and Nd:YAG edge-pumped slab lasers

Experimental demonstrations of two edge-pumped zigzag slab lasers are presented. The Nd:YAG slab laser generated 127 W of multimode output power with 300W of pump power. Preliminary results with a Yb:YAG slab produced 46 W of output power with 315W of pump power. The edge-pumped slab design permits symmetric conduction cooling and efficient pump absorption and accepts large-numerical-aperture pump sources.     

High beam quality and compact diode end-pumped Nd:YVO<Subscript>4</Subscript> slab laser with a hybrid resonator

A compact, high power and high beam quality diode-end-pumped CW Nd:YVO₄ slab 1064 nm laser with a hybrid resonator is demonstrated. The maximum output power of 23.0 W is obtained under the pump power of 66.7 W, which gives the slope efficiency and optical conversion efficiency of 52.0 and 34.0%, respectively. The beam quality M² factors are measured to be 1.5 in the unstable direction and 1.7 in the stable direction. The power stability of the LD end-pumped slab laser at an output power of 19 W is measured to be 0.7% for half an hour operation.     

Optimizing the composite slab sizes in corner-pumped lasers

Using the method of images, a simplified and visualized analytic model to aid in optimizing the geometrical parameters of the corner-pumped composite slab to improve the absorption efficiency is presented. According to the analysis results, the ray trace models are built and simulations are performed. Based on the analytical model and simulation results, the sizes of the composite slabs are optimized to boost the absorption efficiency and pump uniformity. A corner-pumped composite YAG/Yb:YAG slab laser that produced 1016 W continuous wave output power from a single composite crystal, with a slope efficiency and optical-to-optical efficiency of 43% and 34.4%, respectively, was designed. This analysis method may be applied to other obliquely pumped schemes in which the pump direction does not parallel the axis of the resonator.     

High-efficiency high-power QCW diode-side-pumped zigzag Nd:YAG ceramic slab laser

A high-efficiency high-power diode-side-pumped quasi-continuous wave (QCW) Nd:YAG ceramic slab laser using zigzag optical path was demonstrated. With an integrating sphere technique, the scattering and absorption coefficient of the ceramic slab were measured to be 0.0024 and 0.0016 cm^?1 at 1,064 nm, respectively. Under a pump power of 6.69 kW, an average output power of 2.44 kW at 1,064 nm with a repetition rate of 400 Hz was achieved, corresponding to an optical-to-optical efficiency of 36.5 %. As far as we know, this is the highest conversion efficiency reported for QCW side-pumped single slab Nd:YAG ceramic laser.     

CRRFA-30L波段射频加速器

主要介绍CRRFA-30L波段射频加速器结构和性能，论述了热阴极射频腔注入器、束流加速系统、微波功率源和控制等结构中主要技术及其研究进展，给出了加速器输出束流参数测量与测量结果分析，达到设计应用要求。     

Efficient end-pumped slab Nd:YVO4 laser with a multifolded quasi-concentric resonator

A novel end-pumped slab Nd:YVO₄ laser with a multifolded quasi-concentric resonator (FCR) is reported. This planar-folded stable resonator matches the sheet-shaped pump volume with the TEM₀₀ mode and yields highly efficiently laser operation with a good beam quality. In a prototype experiment, a 19.55-W output was achieved with a pump power of 45 W, which was single mode in one direction. In addition, the optical-to-optical efficiency reached 43.4%. After introducing a telescope system into the folding plane, a 10.23-W quasi-TEM₀₀ output was obtained, and the overall efficiency was 22.7%.     

High power Nd:YAG slab laser sidepumped by diode laser array

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A high beam quality laser-diode end-pumped Nd:GdVO<Subscript>4</Subscript> slab laser

An 83 W, near-diffraction-limited LD end-pumped Nd:GdVO₄ slab laser with hybrid resonator was presented with the pumping power of 238 W, the slope efficiency and optical-to-optical conversion efficiency were 39.4 and 34.9%, respectively. At the output power of 70 W, beam quality M² factors were 1.2 in stable direction and 1.3 in unstable direction.     

A compact fir ring laser with open resonator and variable output coupling

We describe the design, construction and first experimental results with an open triangle FIR ring resonator with Michelson interferometer output coupling, which we combined with a Brewster-windowless 10W CO₂ pump laser to a compact laser package of 1m length. The achieved stability of power and frequency of this system is very high, typically on the order of ±0.01% over several hours and <20kHz per hour at 800GHz. For the design, we investigated the balance of all laser processes and determined the optimum dimensions for the open resonator cavity. This analysis is based on a radially homogenous overall laser model, including commonly accepted simplified rate equations together with molecular parameters for weak FIR laser lines. In accordance with the modelling the efficiency on the very most prominent lines is better than with conventional waveguide lasers, giving up to 4 times better efficiencies especially on lines with low absorption pump transitions. Several laser lines, however, have substantially enhanced pump thresholds on purely copropagating emission, suppressing laser operation below about 10W pump power threshold. We show that this can not be due to effects from the interferometer.     

500 W Nd:YAG zigzag slab MOPA laser

A MOPA Nd:YAG laser with end-pumped zigzag slab architecture has been developed. 277 W laser output is obtained from the master-oscillator stage, corresponding to the average slope efficiency of 35.9% and the optical conversion efficiency of 34.6%, which emits the maximum power of 402 with 1163 W of pump power. Furthermore, the amplifier stage produces 505 W with the slope efficiency of 24% and the extraction efficiency of 25%. The beam quality is estimated as M _x ² ≈ 10, M _y ² ≈ 50 in the orthogonal directions respectively.     

An investigation on laser-diode-array pumped Nd: glass slab laser

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激光二极管双端直接抽运混合腔板条激光器

为减少热透镜效应的影响, 获得高光束质量的激光, 本文利用激光二极管阵列双端直接抽运Nd:YVO₄, 采用负支共焦折叠混合腔结构, 获得最高功率为416 W 1064 nm的激光输出, 光–光转换效率为54.3%, 斜效率为61.6%. 在输出功率为370 W时, 光束质量因子M²在非稳腔和稳腔方向上分别为3.9和4.7.     

角抽运Yb:YAG激光器

报道了一种高功率准三能级激光器角抽运方法，抽运光从板条激光器结构中的板条工作介质的角注入，综合考虑抽运吸收、抽运亮度、晶体的掺杂浓度以及晶体尺寸等因素，进行了角抽运复合Yb:YAG激光器设计，实验上获得了最大连续输出功率400W, 斜效率28%的输出，实验结果充分证明了角抽运原理的正确性和应用于高功率激光器方面的可行性. 关键词： Yb:YAG 角抽运 复合晶体     

Thin Nd:YAG slab laser pumped by lens duct coupled diode laser stacks

High power continuous wave operation of a diode face-pumped thin Nd:YAG slab laser is reported. A novel pumping geometry for a thin Nd:YAG slab using cylindrical lens duct coupled diode laser stacks is demonstrated. In a close-coupled resonator, a maximum laser output power of 260 W in multimode operation is obtained. This corresponds to a slope efficiency of 34% and an optical-to-optical efficiency of 27%, respectively. In high-brightness operation, a polarized laser output of 70 W has been obtained with a beam quality factor close to 4 in both directions. The polarization contrast ratio is >100. PACS 42.55.Xi; 42.60.Pk; 42.60.By     

板条固体激光器热稳特性的研究

本文报道板条激光器的热稳运行,在150W至10000W的泵浦功率下输出发散角基本保持不变,最大输出功率大于150W;并绘出了腔内插入柱面镜,以压缩输出激光发散角的初步结果.     

36 W侧面抽运腔内倍频Nd:YAG/KTP连续绿光激光器

通过优化平-凹-平三镜折叠腔结构设计,利用大功率半导体激光器侧面抽运、Ⅱ类相位匹配KTP晶体腔内倍频,获得高效高功率连续绿色激光输出.当抽运电流约为36 A时,得到最高36.6 W的连续绿光激光输出,对应的光—光转换效率为8.71％.在输出功率33 W时测量激光功率稳定性,其功率不稳定度为0.27%.用刀口法测量了激光器高输出功率时的光束质量,光束质量因子小于8.对高功率抽运情况下三镜折叠腔的像散补偿、失调灵敏度和基模在腔内分布情况做了数值模拟. 关键词： 侧面抽运 腔内倍频 连续波     

激光二极管端面抽运Nd:YVO4板条激光器及其热效应

激光器中激光介质采用板条状几何结构可以极大地降低它的热效应,但仍然需要进一步分析其影响,进而优化激光器效率.利用有限元分析方法分析了部分端面抽运的混合腔板条激光器中激光介质的热效应,计算的热透镜焦距与实测结果基本相符.分析了热效应对模式匹配的影响,分析结果对于优化激光器效率、改进谐振腔设计具有一定的参考价值.并在分析的基础上进行了混合腔实验,抽运功率为110 W时,获得连续输出激光功率41.5 W,光光转换效率约38%,斜效率达58.8%,M2因子为非稳腔方向M2x＝1.59,稳定腔方向M2y＝1.55.     

Compact, efficient diode-end-pumped Nd:GdVO4 slab continuous-wave 912-nm laser

A fiber-coupled laser-diode (LD) end-pumped Nd:GdVO₄ slab continuous-wave (CW) 912-nm laser and an LD bar end-pumped Nd:GdVO₄ slab CW 912-nm laser are both demonstrated in this paper. Using the fiber-coupled LD of end-pumped type, a highest CW 912-nm laser output power of 10.17 W is obtained with a high optical-to-optical conversion efficiency of 24.6% and a slope efficiency of 34.5%. The measured M² factors of beam quality in x and y directions are 5.3 and 5.1, respectively. Besides, an LD bar of end-pumped type is used to realize CW 912-nm laser output, which has the advantages of compactness and low cost. When the pump power is 38.8 W, the output power is 8.87 W and the measured M² factors of beam quality in x and y directions are 16 and 1.31, respectively. In order to improve the beam quality of the 912-nm laser at x direction, a new quasi-concentric laser resonator will be designed, and an LD bar end-pumped Nd:GdVO₄ slab high-power CW 912-nm TEM₀₀ laser will be realized in the future.     

103 W in-band dual-end-pumped Ho:YAG laser

An efficient 2?μm in-band pumped Ho:YAG laser was demonstrated. The resonator involves two Ho:YAG crystals, each of which was dual-end-pumped by two orthogonally polarized diode-pumped Tm:YLF lasers. The maximum continuous wave output power of 103?W was achieved, corresponding to a slope efficiency of 67.8% with respect to the incident pump power and an optical-to-optical conversion efficiency of 63.5%. Under Q-switched mode, we obtained 101?W laser output at 30?kHz, corresponding to a slope efficiency of 66.2%. The beam quality or M² factor was found to be less than 2.