An all-solid-state high power quasi-continuous-wave tunable dual-wavelength Ti：sapphire laser system using birefringence filter

This paper describes a tunable dual-wavelength Ti:sapphire laser system with quasi-continuous-wave and high-power outputs. In the design of the laser, it adopts a frequency-doubled Nd:YAG laser as the pumping source, and the birefringence filter as the tuning element. Tunable dual-wavelength outputs with one wavelength range from 700~nm to 756.5~nm, another from 830~nm to 900mn have been demonstrated. With a pump power of 23~W at 532~nm, a repetition rate of 7~kHz and a pulse width of 47.6~ns, an output power of 5.1~W at 744.8~nm and 860.9~nm with a pulse width of 13.2~ns and a line width of 3~nm has been obtained, it indicates an optical-to-optical conversion efficiency of 22.2{\%}.     

Efficient corner-pumped Nd:YAG/YAG composite slab laser

A corner-pumped type is a new pumping type in the diode-pumped all-solid-state lasers, which has the advantages of high pump efficiency and favourable pump uniformity. A highly efficient corner-pumped Nd:YAG/YAG composite slab laser is demonstrated in this paper. The maximal continuous-wave output power of the 1064~nm laser is up to 18.57~W with a slope efficiency and an optical-to-optical conversion efficiency of 44.9{\%} and 39.8{\%}, respectively. Inserting an acousto-optic $Q$-switch in the cavity, the highest average output power of the quasi-continuous wave 1064~nm laser of 6.73~W is obtained at a repetition rate of 9.26~kHz. The experimental results show that a corner-pumped type is a kind of feasible schedules in the design of diode-pumped all-solid-state lasers with low or medium output powers.     

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.     

Two-pass amplification of CW laser by Nd/Cr:YAG ceramic Active mirror under lamp light pumping

The concept of an Active mirror with transparent Nd/Cr:YAG ceramics is proposed. A new ceramic material pumped by an arc-metal-halide lamp has been experimentally implemented. CW-laser light generated in a 1064 nm Nd:YAG micro-tip oscillator was amplified by an Active mirror made of Nd/Cr:YAG ceramic and pumped by CW arc-lamp light. The saturation power density of the Nd/Cr:YAG ceramic was lower than that of Nd:YAG because the stimulated-cross-section and lifetime were effectively enhanced by the sensitization of Cr ions. The maximum output laser power while keeping spatial beam quality was up to 3 W with an input lamp power of 9 W; the resulting optical-optical conversion efficiency of 33% was close to the theoretical prediction of nearly 50%.     

Light scattering and 2-μm laser performance of Tm:YAG ceramic

The scattering effect of Tm:YAG ceramic has been investigated and the scattering coefficient at 1064 nm wavelength is measured to be 0.014 cm⁻¹. Furthermore, a high power Tm:YAG ceramic laser with a slope efficiency of 10.7% has been built, which is end-pumped at a central wavelength of 805 nm. The 2-μm maximum output power is 7.1 W with an optical-optical conversion efficiency of 7.2%.     

108 W Nd: YAG ceramic laser with birefringence compensation resonator

The quartz rotator's effective birefringence compensation for ceramic Nd:YAG rods has been first demonstrated. Furthermore, a high output power continuous-wave laser is presented based on an optimized resonator made up of four Nd:YAG ceramic rods. By an appropriate design of the resonator, an output power of 108 W at 1064 nm is obtained. The corresponding optical-to-optical conversion efficiency is 16.8% and the slope efficiency is 28.1%. Meanwhile, the numerical analysis for output power is detailed.     

钛宝石激光器端面抽运Nd:YAG陶瓷激光器热沉积理论和实验研究

通过热沉积系数研究在激光提取条件下掺杂原子分数为1.0%的Nd:YAG陶瓷激光器中热沉积问题.热沉积系数定义为热沉积功率与激光器输出功率之比.在理论分析基础上，通过测量激光器斜率效率来间接测定热沉积系数，实验测定的热沉积系数值为0.63.建立激光提取条件下Nd:YAG陶瓷发热模型，讨论了影响热沉积系数的主要因素.结果表明：热沉积系数对Nd:YAG陶瓷的辐射量子效率、交叠效率以及激光提取效率的变化非常敏感.为有效减少介质内热沉积，在激光器优化设计中交叠效率和激光提取效率是需要着重考虑的参数.所得结果可为进一步研究陶瓷激光器中热效应提供参考. 关键词： 热沉积 Nd:YAG陶瓷 固体激光器     

Comparison of Nd:YAG Ceramic Laser Pumped at 885nm and 808nm

Laser performance of 1064 nm domestic Nd：YAG ceramic lasers for 885 nm direct pumping and 808 nm traditional pumping are compared. Higher slope efficiency of 34% and maximum output power of 16.5 W are obtained for the 885nm pump with a 6ram length 1 at.% Nd：YAG ceramic. The advantages for 885nm direct pumping are discussed in detail. This pumping scheme for highly doping a Nd：YAG ceramic laser is considered as an available way to generate high power and good beam quality simultaneously.     

Highly efficient diode side-pumped Nd:YAG ceramic laser with 210 W output power

We developed a highly efficient diode side-pumped Nd:YAG ceramic laser with a diffusive reflector as an optical pump cavity. A maximum output power of 211.6 W was obtained with an optical-to-optical conversion efficiency of 48.7%. This corresponds to the highest conversion efficiency in the side-pumped ceramic rod. Thermal effects of the Nd:YAG ceramic rod were analyzed in detail through the measurements of laser output powers and beam profiles near the critically unstable region. A M² beam quality factor of 18.7 was obtained at the maximum laser output power.     

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.     

A high-power high-stability Q-switched green laser with intracavity frequency doubling using a diode-pumped composite ceramic Nd：YAG laser

We successfully obtain a 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 using 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.     

High efficiency,high power QCW diode-side-pumped Nd：YAG ceramic laser at 1064 nm based on domestic ceramic

A high efficiency, high power diode-side-pumped quasi continuous wave （QCW） Nd：YAG ceramic rod laser at 1064 nm based on the domestic transparent ceramic is reported. The average output power of 961 W is achieved with double ceramic rods by means of a symmetrical convex-convex cavity. The optical-to-optical conversion efficiency is 38.3% and the slope efficiency is 45.3%. To the best of our knowledge, this is the highest level of efficiency achieved for the domestic Nd：YAG ceramic rod laser.     

Passively Q-switched Nd:YAG ceramic laser towards large pulse energy and short pulse width

A large pulse energy and high peak power passively Q-switched ceramic neodymium-doped yttrium aluminum garnet (Nd:YAG) laser has been demonstrated with Cr⁴⁺:YAG crystals as the saturable absorbers. By employing a continuous wave (CW) laser-diode (LD) as the pump source, as high as 11.3 W CW output power of 1064 nm was obtained under the pump power of 21.6 W, with an optical conversion efficiency of 52.3%. Inserting different initial transmissions Cr⁴⁺:YAG as saturable absorbers, under the incident pump power of 15.6 W, the largest pulse energy, shortest pulse width, and highest peak power are measured to be 188 μJ, 3.16 ns, and 59.5 kW, respectively. As we has known, this is the best passively Q-switched results ever reported by Nd:YAG ceramic material.     

大功率准连续Nd:YAG陶瓷激光器研究

采用侧面环绕均匀排布的紧凑型抽运结构,实现了激光二极管阵列侧向抽运Nd∶YAG陶瓷激光器高效率激光输出。理论计算得到谐振腔输出镜的最佳输出耦合透射率为22.2%,并在输出耦合镜透射率为22%的条件下,用掺杂原子数分数为1%,尺寸为5mm×75mm的Nd∶YAG陶瓷棒,获得了平均功率大于230W的准连续1064nm激光输出,其光光效率和斜率效率分别高达52.4%和61%。并测得输出激光脉冲宽度为160μs,光谱线宽略小于0.8nm,光束发散角为16mrad。实验结果显示,Nd∶YAG陶瓷激光器输出功率Nd∶YAG单晶激光器相当。     

High power high beam quality diode-pumped 1319-nm Nd:YAG oscillator-amplifier laser system

This paper demonstrated a high power and high beam quality diode-pumped 1319-nm Nd:YAG master oscillator-power amplifier laser system. A thermally near-unstable resonator with four-rod birefringence compensation flat--flat cavity was adopted as the master oscillator. A solid etalon was inserted in the unidirectional ring resonator to compress the laser linewidth. Under a repetition rate of 500~Hz and pulse width of 160~\mus, the master oscillator delivers an average output power of 16.8~W at 1319~nm with linear polarisation, beam quality factor M^{2} = 1.16 and linewidth of 3.2~GHz. A double-pass power amplifier with two amplifier stages was employed for higher power scaling and the output power was amplified to be 25.9~W with M^{2} = 1.43.     

Side-pumped continuous-wave Cr:Nd:YAG ceramic solar laser

To clarify the advantages of Cr:Nd:YAG ceramics rods in solar-pumped lasers, a fused silica light guide with rectangular cross-section is coupled to a compound V-shaped cavity within which a 7 mm diameter 0.1 at.% Cr:1.0 at.% Nd:YAG ceramic rod is uniformly pumped. The highly concentrated solar radiation at the focal spot of a 2 m diameter stationary parabolic mirror is transformed into a uniform pump radiation by the light guide. Efficient pump light absorption is achieved by pumping uniformly the ceramic rod within the V-shaped cavity. Optimum pumping parameters and solar laser output powers are found through ZEMAX^© non-sequential ray-tracing and LASCAD^© laser cavity analysis codes. 33.6 W continuous-wave laser power is measured, corresponding to 1.32 times enhancement over our previous results with a 4 mm diameter Nd:YAG single-crystal rod. High slope efficiency of 2.6 % is also registered. The solar laser output performances of both the ceramic and the single-crystal rods are finally compared, revealing the relative advantage of the Cr:Nd:YAG rod in conversion efficiency. Low scattering coefficient of 0.0018 cm^?1 is deduced for the ceramic rod. Heat load is considered as a key factor affecting the ceramic laser output performance.     

660 nm单一波长Nd:YAG陶瓷激光器

 针对陶瓷晶体1319 nm的谱线设计了适合的谐振腔腔镜膜系参量,采用激光二极管列阵侧向抽运掺杂1.1at%、Φ3×50 mm的Nd:YAG陶瓷,利用色散棱镜及KTP晶体Ⅱ类匹配腔内倍频,研制了一台660 nm单一波长输出的高重频Nd:YAG陶瓷红光激光器.根据陶瓷晶体的热透镜焦距设计了谐振腔的各个参量,在重复频率为1000 Hz、单脉冲抽运能量约144 mJ时,获得了3.9 mJ的660 nm脉冲激光输出,总的光-光转换效率为2.71%.为进一步研究大功率、高效率的陶瓷红光激光器奠定了基础.     

Compact and efficient diode-pumped actively Q-switched 1319 nm Nd:YAG ceramic laser

An efficient compact diode-pumped acousto-optic actively Q-switched Nd:YAG ceramic laser operating at 1319 nm was demonstrated. At an incident pump power of 23.7 W, an average output power of 4.8 W at a pulse repetition frequency of 30 kHz was obtained. The corresponding optical-to-optical conversion efficiency was 20.3%. A maximum single pulse energy of 316 μJ with a pulse duration of 78.5 ns was obtained at an incident pump power of 19.4 W and a pulse repetition frequency of 10 kHz.     

国产掺Nd3+透明薄片陶瓷的光学性能研究

研究了国产透明陶瓷Nd∶YAG和Nd∶YSAG的光学和激光性能.介绍了透明陶瓷Nd∶YAG和Nd∶YSAG的制作方法及其光谱性能,报道了相应的激光实验结果.对于Nd∶YAG薄片激光器,得到了中心波长1 064.2 nm,半高全宽为0.89 nm的激光输出,泵浦阈值功率0.267 W,最大激光输出功率0.319 W.对于Nd∶YSAG薄片激光器,由于荧光寿命比较长,可实现高掺杂,输出激光的中心波长为1 063.8 nm,半高全宽为1.6 nm,最大激光输出功率为0.356 W,斜率效率达23.2％,结果证明国产Nd∶YSAG陶瓷适用于短脉冲薄片激光器.     

The first-stokes pulse generation in Nd:KGW intracavity driven by a diode-pumped passively Q-switched Nd:YAG/Cr<Superscript>4+</Superscript>:YAG laser

The operation of an all solid-state pulsed Nd:KGW Raman laser pumped by compact passively Q-switched Nd:YAG/Cr:YAG laser is demonstrated. The first-Stokes radiation of stimulated Nd:KGW Raman scattering at the 1178 nm is generated. The average output power of 336 mW at Stokes wavelength was obtained under the laser diode pump power of 5.74 W. The corresponding optical efficiency from the diode light to the Raman output is 9.85%. The pulse width of 1.65 ns and a pulse repetition rate of 10 kHz were also obtained.