CW red light generated by intracavity frequency doubling of a 1329 nm Nd:CNGG laser with LBO

We report an efficient laser emission on the 1329 nm ⁴ F _3/2 to ⁴ I _13/2 transition in Nd:CNGG under the pump with diode laser at 885 nm. Continuous wave (CW) 3.37 W output power at 1329 nm is obtained under 17.4 W of incident pump power; the slope efficiency with respect to the incident pump power was 36.2%. Moreover, intracavity frequency doubling with LiB₃O₅ (LBO) nonlinear crystal yielded 822 mW of red light at 665 nm. An optical-to-optical efficiency with respect to the incident pump power was 4.7%.     

Efficient red light generated by intracavity frequency doubling of a 1331 nm Nd:GGG laser with LBO

We report a continuous-wave (CW) coherent red radiation at 666 nm by intracavity frequency doubling generation of 1331 nm Nd:GGG laser. With incident pump power of 18.3 W, output power of 910 mW at 666 nm has been obtained using a 10 mm-long LBO crystal. At the output power level of 910 mW, the output stability is better than 5%. The beam quality M ² values were equal to 1.21 and 1.34 in X and Y directions, respectively.     

腔内倍频Nd:YVO4晶体激光获得的大功率671nm红光

本文报道了由双端泵浦Nd:YVO4晶体产生1342nm基频光，经过非线性晶体LBO腔内产生的671nm的红光光源。泵浦功率19.5W时，产生的671nm的红光平均功率是2.9W。光光转换效率为14.9%。分析了最近泵浦光斑尺寸，最佳聚焦位置，减少热透镜效应对输出功率的影响。双端泵浦结构和准连续运行模式大大减弱了热透镜效应。     

Optimization of intracavity Q-switched laser frequency doubling

The optimization theory for intracavity frequency-doubled Q-switched lasers is discussed. Nonlinear loss effects caused by the frequency doubler were introduced into the rate equations. The harmonic pulse characteristics such as peak power, pulse energy, pulsewidth were studied. Lagrange multiplier technique was adopted to maximize the peak power of the second-harmonic pulse for a given pumping level. It was found that the optimal frequency-doubling factor is constant and equals 1. Design curves for the laser characteristics parameter were established. The curves and expressions presented help in designing an optimal Q-switched intracavity frequency-doubled miniature laser and predict the pulse characteristics.     

60 W yellow laser at 561 nm by intracavity frequency doubling of a diode-pumped Q-switched Nd:YAG laser

A high-power yellow laser was achieved by intracavity frequency doubling of a diode-pumped Nd:YAG rod laser. A solid etalon was inserted into the resonator to implement efficient operation of the low-gain single line at 1123 nm transition. By using a LBO crystal inside the cavity as the frequency doubler, the maximum output power of the 561 nm yellow laser was obtained to be as high as 60.3 W with a pulse repetition frequency of 6 kHz, corresponding to an optical-to-optical conversion efficiency of about 6.1%. The output power fluctuation of the yellow laser was measured to be better than 3% in half an hour.     

High-power high-stability Q-switched green laser with intracavity frequency doubling of diode-pumped composite ceramic Nd:YAG laser

We successfully obtain high-average-power high-stability Q-switched green laser based on diode-side-pumped composite ceramic Nd:YAG in a straight plano-concave cavity. The temperature distribution in composite ceramic Nd:YAG crystal is numerically analyzed and compared with that of conventional Nd:YAG crystal. By use of a composite ceramic Nd:YAG rod and a type-II high gray track resistance KTP (HGTR-KTP) crystal, a green laser with an average output power of 165 W is obtained at a repetition rate of 25 kHz, with a diode-to-green optical conversion of 14.68%, and a pulse width of 162 ns. To the best of our knowledge, both the output power and optical-to-optical efficiency are the highest values for green laser systems with intracavity frequency doubling of this novel composite ceramic Nd:YAG laser to date. The power fluctuation at around 160 W is lower than 0.3% in 2.5 hours.     

1064 nm Nd:YAG laser intracavity pumped at 946 nm

We present for the first time a Nd:YAG laser emitting at 1064 nm intracavity pumped by a 946 nm diode-pumped Nd:YAG laser. A 885 nm laser diode is used to pump the first Nd:YAG crystal emitting at 946 nm, and the second Nd:YAG laser emitting at 1064 nm intracavity pumped at 946 nm. We achieved an output power of 7.97 W at 1064 nm for an absorbed pump power at 946 nm of 9.55 W, corresponding to an optical efficiency of 83.4%. The beam quality M² quality factor is about 1.1 at the maximum output power.     

LD-end-pumped Nd:YAP laser operating at 1341.4 nm and doubling of its frequency

We report an LD-end-pumped linearly-polarized continuous-wave (CW) Nd:YAP laser operating at 1341.4 nm. Making use of the plane-concave resonator (T = 2.4%) and the plane-plane resonator (T = 2.6%), we obtain linearly-polarized laser radiation at 1341.4 nm with a power of 3.15 and 2.86 W and corresponding optical slope efficiency of 18.4 and 17.5%, respectively. The effect of the laser oscillation mode on the output is analyzed. An experiment on the intra-cavity frequency doubling with an LBO crystal has been performed, and a laser power of 431 mW in one direction at 670.7 nm was obtained.     

Continuous-wave green laser of 34 W by intracavity frequency doubling in diode-side-pumped Nd:YAG/KTP

Continuous-wave green laser with a maximum power of 34 W has been obtained by intracavity frequency doubling with KTP in diode-side-pumped Nd：YAG. The Nd：YAG/KTP green laser has a simple three- mirror V-fold cavity structure. The optical-to-optical conversion efficiency is 9.5%. The instability of the laser is measured when the output powers are near 16, 21, 30, and 34 W after the beam is filtered. At the maximum output power, the M^2 factor is measured to be 8.     

全固态腔内倍频被动调Q黄光激光器理论研究

考虑晶体热衍射损耗以及在倍频过程中的非线性腔内损耗的影响,给出了LD泵浦Cr:YAG被动调Q556nm激光的耦合速率方程,数值求解了该方程组获得输出激光的重复频率,平均输出功率,峰值功率随泵浦功率的变化特性,理论值与实验结果符合较好.     

全固态腔内倍频被动调Q绿光激光器的理论研究

将倍频过程视为一种随基波光子数变化而变化的非线性腔内损耗,对被动调Q四能级速率方程进行修正,总结出了被动调Q绿光激光器的四能级非线性速率方程.通过数值求解,对连续LD泵浦Nd:GdVO4 /Cr4+:YAG/KTP和Nd:YAG/ Cr4+:YAG/LBO腔内倍频被动调Q绿光激光器的输出特性进行了数值模拟.通过与实验数...     

Efficient generation of blue light by intracavity frequency doubling of a cw Nd:YAG laser with LBO

We report on the efficient room-temperature operation of ⁴F_3/2–⁴I_9/2 transition in a diode pumped Nd:YAG laser operating at 946 nm. An output power of 5.1 W and a slope efficiency of 23.6% at 946 nm have been obtained. Different LBO crystals of length 3×3×10 mm³, 3×3×15 mm³, 3×3×18 mm³ were selected as frequency doubling material for comparison. A maximum single-ended output power of 1.3 W at 473 nm was achieved by frequency doubling with an optical conversion efficiency of 5%. When the Nd:YAG rod was replaced by the one with high reflectivity coating at 473 nm on the pump side, the output power of blue light was almost twice that without high reflectivity coating for 473 nm at the same pump power level. Moreover, the theoretical optimum length of LBO crystal for intracavity frequency doubling was discussed, and the experimental results made a good agreement with it.     

Blue laser light generation by intracavity frequency doubling of Cesium vapor laser

Blue laser light with a wavelength 447 nm was generated by intracavity frequency doubling of a Cs laser in PPKTP crystal. A continuous wave power of 600 mW was obtained at an optical-to-optical efficiency of 4%. In the pulsed operation, when thermal effects were reduced, the efficiency obtained was 14% and the peak blue power was 2.1 W.     

Compact efficient diode-end-pumped intracavity frequency-tripled Nd:YAG 355 nm laser

A compact efficient diode-end-pumped acousto-optically Q-switched intracavity-frequency-tripled Nd:YAG 355 nm ultraviolet laser was realized. Intracavity sub-resonators with anti-reflection and high-reflection coated mirrors were used to get higher efficiency of third harmonic generation. With two LBO crystals used in frequency doubling and tripling processes respectively, greater than 1.2 W 355 nm average output power was obtained under the absorbed pump power of 10 W and the repetition rate of 5 kHz. The corresponding pump-to-ultraviolet conversion efficiency was determined to be as high as 12%. At 5 kHz, the minimize pulse width was obtained to be 14.2 ns with the peak power of 16.9 kW and single pulse energy of 240 μJ. The instability of the 355 nm laser was measured to be less than 4.2% at an output power of 0.9 W within half an hour operation.     

紧凑型激光二极管抽运全固态355 nm连续波紫外激光器

报道了一台激光二极管端面抽运Nd:YVO₄晶体内腔三倍频355 nm激光连续输出的全固态紫外激光器.激光腔采用紧凑型简单凹平直腔,腔长仅为70 mm.利用两块LBO晶体进行腔内倍频、和频,当注入抽运功率为2527 W时,获得最大功率为306 mW的355 nm连续波输出,光光转换效率为012％,输出功率短期不稳定性为53%,355 nm激光输出光束质量良好.通过采用内腔倍频技术和设计合理的腔参数,实现了中小功率连续输出的全固态紫外激光器的小型化、便携化,进一步拓宽了紫外激光器 关键词： 激光二极管端面抽运 内腔三倍频 连续波 355 nm激光     

Diode-pumped eye sensitive laser at 554.7 nm based on intracavity sum frequency generation

We report for the first time a coherent radiation at 554.7 nm by intracavity sum-frequency generation of 946 nm Nd:YAG laser and 1341 nm Nd:YAP laser. Yellow-green laser is obtained by using a doubly folded cavity, type-II critical phase matching KTP crystal sum-frequency mixing. With total pump power of 36.1 W (17.8 W pump power for 1341 nm Nd:YAP laser and 18.3 W pump power for 946 nm Nd:YAG laser), TEM₀₀ mode yellow-green laser at 554.7 nm of 1.43 W is obtained.     

High average power Q-switched green beam generation by intracavity frequency doubling of diode-side-pumped Nd:YAG/HGTR-KTP laser

To obtain high power and high beam quality second harmonic generation, a Q-switched system has been demonstrated by intracavity frequency doubling of two diode-side-pumped Nd:YAG modules with double AO-modulators in an astigmatism compensated cavity geometry. A maximum average frequency doubled power of 185 W is obtained when the pumping power is 600 W for each module. The corresponding optical-to-optical conversion efficiency is 15.4% and the pulse width is 180 ns at a repetition rate of 10 kHz. An instability of 2.5% was measured over a period of 2 h and the beam quality factors were measured to be , the maximum output power.     

456-nm deep-blue laser generation by intracavity frequency doubling of Nd:GdVO4 under 879-nm diode pumping

We report on a simple, compact continuous-wave 456-nm laser by intracavity frequency doubling of an end-pumped Nd:GdVO₄ laser on the ⁴ F _3/2 → ⁴ I _9/2 transition. A 5-mm-long, 0.2-at % Nd:GdVO₄ bulk crystal is employed as the gain medium and the Nd³⁺ ion is directly pumped into the emitting level (⁴ F _3/2) by a novel 879-nm laser diode. Intracavity frequency doubling with a 15-mm-long LBO crystal and a 10-mm-long BiBO crystal in a linear cavity yield 56- and 118-mW single-ended blue outputs at the absorbed pump power of 11.9 W, respectively. The corresponding values are scaled to 286 and 391 mW, respectively, in a V-type cavity, with optical conversion efficiencies of 2.4 and 3.3% versus the absorbed pump power. The fluctuations of the 456-nm output power for both cases are less than 3% at the maximum output level.     

Diode pumped Nd:GSAG and Nd:YGG laser at 942 and 935 nm

Two new Nd³⁺ doped crystals show laser activity between the ⁴F_3/2 and ⁴I_9/2 levels. Diode pumped emission of Nd:GSAG at 942 nm wavelength with 950 mW output power and 14% optical to optical efficiency as well as laser emission of Nd:YGG at 935 nm with 700 mW output power and 11% efficiency have been obtained. These wavelengths are useful for water vapour absorption measurements.     

LD抽运Nd：YAG／KTP腔内倍频连续绿光激光器实验研究

设计了LD端面抽运固体激光器平台,研究了LD抽运Nd:YAG/KTP腔内倍频连续绿光的输出特性、光-光转换效率、输出功率稳定性,并实验验证了倾斜反射镜的选模效果.该系统实现了基横模绿光输出,椭圆度达0.96.