High power single-longitudinal-mode operation in a twisted-mode-cavity laser with a c-cut Nd:GdVO4 crystal

A twisted-mode-cavity laser was established by using a piece of c-cut Nd:GdVO₄ crystal as the lasers active material. Output spectra were scanned by a scanning Fabry–Perot interferometer, which demonstrated that the single-longitudinal-mode laser operation was realized in the twisted-mode-cavity laser configuration. A maximum single-longitudinal-mode laser output power of 2.1 W was obtained when the pump power was 11.5 W. The pump slope efficiency was about 20.0%. A passively Q-switched single-longitudinal-mode laser was also achieved in a twisted-mode cavity by inserting a piece of Cr⁴⁺:YAG as an intracavity saturable absorber. The Q-switched single-longitudinal-mode laser pulse duration was measured to be 100 ns and the single-pulse energy was about 40.0 J.     

High power single-mode large-mode-area photonic crystal fiber laser with improved Fabry-Perot cavity

An Yb3+-doped double-clad large-mode-area photonic crystal fiber (LMA PCF) laser with 103-W single mode continuous-wave output power is demonstrated using an improved Fabry-Perot (F-P) configuration.The slope efficiency of 83.2% and good beam quality (M2 = 1.2 ± 0.1) are achieved without any thermo optical problems,dichroic mirror surface damage,and drop of the slope efficiency in this system.     

High power red laser generation by second harmonic generation with GTR-KTP crystal

In this Letter, a gray-tracking-resistant—potassium titanyl phosphate(GTR-KTP) crystal is used for intracavity frequency doubling red laser generation for the first time. Under the 808 nm LD pump power of 180 W, as high as 12.5 W of red laser output is obtained with the optimum repetition rate of 7 k Hz. Within the red laser power variation range between the maximum to 70%, a temperature tolerance is measured to be 35°C. The results prove that GTR-KTP should be a potential nonlinear crystal for red laser generation.     

High power low-order modes operation of a multimode fiber laser

Coiling technique is used to suppress high-order modes of a large mode area (LMA) double clad multimode fiber. Output powers and beam quality factors M2 are measured under two different coiling radii. 217 W with M2 of 2.96 can be obtained for coiling radius of 165 mm and 160 W with M2 of 1.38 for 52 mm. The corresponding slope efficiencies are 60% and 48%. With smaller coiling radius, the brightness is 3.4 times as high as that of the larger one.     

High power single transverse mode operation of a tapered large-mode-area fiber laser

To get high output power with good beam quality, a tapered section is introduced to large-mode-area (LMA) Yb-doped fiber laser. Output characteristics of the fiber laser without tapered section and with tapered section are compared experimentally. When the launched pump power is 119.1 W, 77.9 W with M² 3.08 and 56.4 W with M² 1.14 can be obtained, respectively. The corresponding slope efficiencies are 71.8% and 54.1%, respectively. Although output power of the tapered fiber laser has 30.6% penalty, brightness of it is as much as 5.28 times of the fiber laser without tapered section. Moreover, spectra of them are measured. It is found that tapered section makes lasing wavelength of the fiber laser shorter.     

High power operation of a CW 28 μm water vapor laser

This paper describes the best operating conditions and power performance of a CW 28 μm water vapor laser, using a 3 m long discharge in a 3 cm diameter Pyrex glass tube. The laser cavity is a half symmetric conventional Fabry-Perot resonator, the plane mirror of which is a metal mesh used as an output coupler. The addition of a large amount of hydrogen to the water vapor leads to the production of high power laser emission. This laser delivers 230 mW of continuous output at 28 μm, corresponding to a volumetric power of 102 μW/cm³, the highest value ever reported.     

High power Q-switched Yb-doped photonic crystal fiber laser producing sub-10 ns pulses

We report on a Q-switched fiber laser producing pulse durations well below 10 ns by using a short-length ytterbium-doped rod-type photonic crystal fiber as gain medium. At repetition rates up to 100 kHz pulse energies up to 0.5 mJ and average powers in excess of 30 W have been obtained in single-transverse mode beam quality. The compact short pulse laser system possesses further power and energy scaling potential.     

高峰值功率KDP晶体四倍频266nm紫外激光器

报道了一种灯泵浦结构的Nd:YAG晶体电光调Q高峰值功率266nm紫外激光器。结合磷酸二氢钾(KDP)晶体性质,基于倍频理论,分析了考虑走离效应情况下存在相位失配量时KDP晶体长度对转换效率的影响。该激光器采用紧凑的平平腔结构,灯泵浦Nd:YAG晶体电光调Q 1064nm激光作为基频光,腔外采用Ⅱ类匹配磷酸钛氧钾(KTP)和Ⅰ类匹配KDP分别作为二倍频和四倍频晶体。利用能量计、示波器等仪器进行测量,激光器重复频率1Hz时,获得脉宽6.0ns,单脉冲能量35mJ的266nm紫外激光输出,峰值功率高达5.83 MW;当重复频率10Hz时,获得单脉冲能量28.9mJ的266nm紫外激光。532~266nm转换效率最高可达31.9%。利用该高峰值功率、窄脉宽266nm紫外激光器,能够实现激光打标、激光雕刻。     

高峰值功率KDP晶体四倍频266 nm紫外激光器

报道了一种灯泵浦结构的Nd:YAG晶体电光调Q高峰值功率266 nm紫外激光器。结合磷酸二氢钾(KDP)晶体性质,基于倍频理论,分析了考虑走离效应情况下存在相位失配量时KDP晶体长度对转换效率的影响。该激光器采用紧凑的平平腔结构,灯泵浦Nd:YAG晶体电光调Q 1064 nm激光作为基频光,腔外采用Ⅱ类匹配磷酸钛氧钾(KTP)和Ⅰ类匹配KDP分别作为二倍频和四倍频晶体。利用能量计、示波器等仪器进行测量,激光器重复频率1 Hz时,获得脉宽6.0 ns,单脉冲能量35 mJ的266 nm紫外激光输出,峰值功率高达5.83 MW;当重复频率10 Hz时,获得单脉冲能量28.9 mJ的266 nm紫外激光。532~266 nm转换效率最高可达31.9%。利用该高峰值功率、窄脉宽266 nm紫外激光器,能够实现激光打标、激光雕刻。     

高功率固体激光驱动器能源系统线路结构优化实验研究

 高功率固体激光驱动器能源系统主要为闪光灯提供脉冲能量。在对能源系统的研究中,通过采用具有预电离技术的电容器一端接地的电路结构,选用新品低损耗电缆及其它措施,有效地抑制了电磁干扰和地电位抬高,提高了电路的能量转换效率,从而满足了惯性约束聚变驱动器对能源系统的要求。尤其加预电离后,闪光灯放电电流波形发生变形有利于提高放大器效率的变化。     

高功率固体激光驱动器能源系统线路结构优化实验研究

高功率固体激光驱动器能源系统主要为闪光灯提供脉冲能量。在对能源系统的研究中,通过采用具有预电离技术的电容器一端接地的电路结构,选用新品低损耗电缆及其它措施,有效地抑制了电磁干扰和地电位抬高,提高了电路的能量转换效率,从而满足了惯性约束聚变驱动器对能源系统的要求。尤其加预电离后,闪光灯放电电流波形发生变形有利于提高放大器效率的变化。     

High power CW laser operation with a Nd:YAG single-crystal fiber grown by LHPG method

We report a high power continuous wave laser operation with a Nd:YAG single crystal fiber. A piece of high quality Nd:YAG single crystal fiber was prepared by means of laser heated pedestal growth method and was then applied as the laser gain medium. The crystal fiber laser was end-pumped by a fiber pig-tailed laser diode working around 808 nm. A maximum output power of 13 W was obtained at a pump power of 60 W. To our knowledge, it was the highest laser power ever achieved with a piece of single crystal fiber.     

High power semiconductor laser array with single-mode emission

The semiconductor laser array with single-mode emission is presented in this paper. The 6-μ m-wide ridge waveguides (RWGs) are fabricated to select the lateral mode. Thus the fundamental mode of laser array can be obtained by the RWGs. And the maximum output power of single-mode emission can reach 36 W at an injection current of 43 A, after that, a kink will appear. The slow axis (SA) far-field divergence angle of the unit is 13.65°. The beam quality factor M² of the units determined by the second-order moment (SOM) method, is 1.2. This single-mode emission laser array can be used for laser processing.     

High power vertical-external-cavity surface-emitting laser

<正>A high power optically-pumped vertical-external-cavity surface-emitting laser with a diamond heatspreader is demonstrated.Owing to the good thermal conductivity,diamond can accelerate the dissipation of heat in the active region and increase the output power significantly.The effects of the curvature radius,the transmission of output coupler,the spot size of the pump,and the temperature of the heat sink on the output power are investigated.A maximum output power of 880 mW is obtained under the conditions of 10℃temperature,15-mm curvature radius,3%transmission of the output coupler,and 8500-mW pump power.The slope efficiency and the optical-to-optical conversion efficiency of the laser are about 17%and 15%,respectively.     

高功率二极管泵浦腔内倍频激光器

 成功研制了一台高功率二极管泵浦声光Q开关腔内倍频Nd:YAG激光器。当泵浦功率约为350W时，采用透过率为30%的输出耦合镜，调Q激光输出功率32.5W，脉宽约200ns，重复频率7kHz；采用Ⅱ类匹配KTP晶体腔内倍频，获得了32.5W的绿光输出，脉宽约120ns。输出光束平滑，远场为类高斯分布，测得的光束质量因子为3.6。     

浮区区熔生长的单晶光纤形状稳定问题

本文用晶体区熔生长理论对激光加热基座法生长的单晶光纤形状稳定问题作了研究.说明了稳定生长的熔区长度与晶纤直径、源棒直径的关系.讨论了影响晶纤直径波动的干扰因素.指出了干扰因素中激光功率的稳定和源棒直径的均匀是主要的.理论推出的结论得到实验证实.     

High peak power operation and harmonic generation of a single-polarization, Yb-doped photonic crystal fiber amplifier

We report on the use of a single-polarization, 41 μm core-diameter, intrinsically single-mode photonic crystal fiber (PCF) to obtain high peak power (up to 800 kW), 1 ns-duration pulses in a 100:1 linearly polarized, intrinsically single-mode (M²  1.2) output. By transmitting the PCF output through nonlinear crystals, we also obtained efficient second, third, and fourth harmonic generation resulting in peak power >400 kW in the visible (green, 531 nm) and 200 kW in the UV (265.5 nm). To our knowledge these results represent the highest peak power obtained in a linearly polarized output from a fiber and the highest peak power in the visible and UV obtained through harmonic generation of the direct fiber output.     

47-wavelength flat erbium-doped fiber ring laser with reduced operation power

A 47-wavelength flat erbium-doped fiber ring laser over whole C-band is experimentally achieved with only 21-dBm output power from erbium-doped fiber amplifier (EDFA). The spectrum flatness of the multiwavelength erbium-doped fiber laser (EDFL) is investigated.     

High power CW and diode-side-pumped Q-switched operation of a Nd：YAG 1319-nm laser

We demonstrated the highly efficient continuous wave （CW） and Q-switched infrared laser from a diode- side-pumped Nd：YAG crystal. A CW output as high as 66 W at 1319 nm was achieved under the pump power of 460 W, corresponding to a coversion efficiency of 14.3%. A maximum average power of 8.9 W of TEM00 mode was obtained in Q-switched operation at the repetition rate of 8 kHz. The performance of the laser considering the thermal lens effect induced by pump power was also analyzed.     

High power CW and Q-switched operation of a diode-side-pumped Nd: YAG 1319-nm laser

We demonstrated the highly efficient continuous wave(CW)and Q-switched infrared laser from a diodeside-pumped Nd:YAG crystal.A CW output as high as 66 W at 1319 nm was achieved under the pump power of 460 W,corresponding to a coversion efficiency of 14.3%.A maximum average power of 8.9 W of TEM00 mode was obtained in Q-switched operation at the repetition rate of 8 kHz.The performance of the laser considering the thermal lens effect induced by pump power Was also analyzed.