基于LD双端面泵浦的Nd:YAG高效率倍频激光器

报道了一种利用激光二极管（LD）双端面泵浦的Nd：YAG激光晶体,Cr⁴⁺：YAG晶体被动调Q,LBO临界相位匹配腔内倍频的高转换效率的绿光激光器。分析了双端面泵浦YAG激光器的热效应,实验中LD双端面泵浦,采用U型平行平面腔结构对Nd：YAG进行传导冷却。当总泵浦光为33.8 W时,得到被动调Q频率10 KHz、功率8.21 W的线偏振基频光输出。6.72 W的绿光输出的倍频效率为86%,输出光束为基模,M²为1.4。实验表明双端面泵浦YAG倍频激光器具有很高的转换效率。     

非对称结构大功率940nm量子阱激光器

为改善940 nm大功率InGaAs/GaAs半导体激光器输出特性,通过模拟计算了非对称波导层及限制层结构的光场分布,并参照模拟制作了非对称结构半导体激光器器件。采用低压金属有机物气相沉积(LP-MOCVD)生长技术,获得了低内吸收系数的高质量外延材料,通过实验数据计算得到激光器材料内吸收系数仅为0.44mm~(-1)。进而通过管芯工艺制作了条宽100μm、腔长2000μm的940 nm半导体激光器器件。25℃室温10 A直流连续(CW)测试镀膜后器件阈值电流251 mA,斜率效率1.22 W/A,最大输出功率达到9.6 W,最大光电转化效率超过70%。     

Free-running emerald laser pumped by laser diode

Free-running emerald laser pumped by 660-nm laser diode (LD) was reported. Free-running output powerof 24 mW has been obtained with overall efficiency of 1.4% and slope efficiency of 11.9% when the LD incident power was 2.56 W. The laser threshold value of emerald crystal was estimated to be 0.7 W.     

A High Conversion Efficiency Q-Switched Intracavity Nd:YVO_4/KTA Optical Parametric Oscillator under Direct Diode Pumping at 880nm

We report a high conversion efficiency Q-switched Nd:YVO_4/KTiOAsO_4(KTA) intracavity optical parametric oscillator(IOPO) operating near 3.5 um based on direct 880 nm laser diode(LD) pumping. A maximum average idler output power of 2.6 W with a pulse width of about 7.9 ns is achieved under an absorbed LD power of 45.4 W at a pulse repetition rate(PRR) of 10 kHz. The maximum optical-optical conversion efficiency from LD power to OPO mid-infrared(MIR) output of 6.74% is achieved. To our knowledge, this is the highest conversion efficiency for a KTA-IOPO by exploiting a Q-switched laser as the parent fundamental pump source. The beam quality factors M~2 of the MIR beam at the full output power with a PRR of 10 kHz are within 2.12 in both the horizontal and vertical directions, indicating a near Gaussian mode.     

Watt-level Pr~(3+):YLF deep red laser pumped by a fiber-coupled blue LD module or a single-emitter blue LD

A power-scaled laser operation of Pr:YLi F4(YLF)crystal at 720.9 nm pumped by a 443.6 nm laser diode(LD)module was demonstrated.The 20 W module was used to pump the Pr:YLF crystal,and a maximum output power of 3.03 W with slope efficiency of 30.04%was obtained.In addition,a 5 W blue LD was also used to pump the Pr:YLF laser,and a maximum output power of 0.72 W was obtained at room temperature.The output power was limited by the wavelength mismatch between the single-emitter LD and the absorption peak of the crystal.     

Efficient continuous-wave eye-safe region signal output from intra-cavity singly resonant optical parametric oscillator

We report an efficient continuous-wave (CW) tunable intra-cavity singly resonant optical parametric oscillator based on the multi-period periodically poled lithium niobate and using a laser diode (LD) end-pumped CW 1064 nm Nd:YVO₄ laser as the pump source. A highly efficiency CW operation is realized through a careful cavity design for mode matching and thermal stability. The signal tuning range is 1401-1500 nm obtained by varying the domain period. The maximum output power of 2.2 W at 1500 nm is obtained with a 17.1 W 808 nm LD power and the corresponding conversion efficiency is 12.9%.     

激光二极管泵浦Nd：YVO4／LBO腔内倍频瓦级连续波绿光激光器

报道一种激光二极管端面泵浦ＮｄＹＶＯ４晶体、ＬＢＯ腔内倍频的全固态瓦级连续波（ＣＷ）绿光激光器。对ＬＢＯ采用Ｉ类非临界相位匹配（ＮＣＰＭ）、温度调谐，当泵光功率为５．５Ｗ时，获得了１．２ＷＴＥＭ００模５３２ｎｍ连续波绿光输出，光－光转换效率达２２％，电－光转换效率达３％。     

Efficient parametric interactions in a low loss GaInP photonic crystal waveguide

We describe time domain characterizations of dynamic four-wave mixing in a low loss modified W1 GaInP photonic crystal waveguide. Using 32 ps wide pump pulses with peak powers of up to 1.1 W we achieved a very large conversion efficiency of -6.8 dB as well as a 1.3 dB parametric gain experienced by a weak CW probe signal. Time domain simulations confirm quantitatively all the measured results.     

A MOPA with double-end pumped configuration using total internal reflection

We presented a Nd:YAG master oscillator power amplifier (MOPA) with the compact LD double-end pumped configuration. To acquire the homogenous absorption distribution, a composite short Nd:YAG rod has been employed as the amplification medium and the rod side was well polished to cause total internal reflection (TIR) at the internal wall of the rod. Because the axes of pump LDs and the seed laser occupy the same position, it is relatively easy to obtain both the satisfied mode-matching efficiency and the high absorption efficiency by using two stacked-LD modules. A seed laser, with the input energy of 15 mJ and the pulse width of 46 ns, was amplified through the MOPA structure with the one-pass gain of about 1.2. We have not found any parasitic oscillations from both ends of the amplifier rod until the total pump LD power reached 420 W. The proposed scheme is thought to be useful in a multiple-pass MOPA system for high-average-power applications.     

LD侧泵Nd∶YAG/S-KTP腔内倍频高功率660nm连续红光激光器

报道了LD侧面泵浦Nd∶YAG/S-KTP腔内倍频高功率660nm连续红光激光器。泵浦组件（呈三角形等间距分布）由9个20W的激光二极管组成，最大泵浦功率为180W。通过对谐振腔参数进行优化设计，用LD连续抽运3mm×65mm Nd∶YAG激光棒时，获得了波长为1319nm的基频光振荡。利用S-KTP II类临界相位匹配腔内倍频技术，当泵浦电流为22A时，获得了6.8W的连续红光激光输出，光-光转换效率为4.3％。     

High efficiency passive mode-locked Nd:YVO<Subscript>4</Subscript> laser based on SESAM under direct pumping at 880 nm

We report on an 880 nm LD pumped passive mode-locked TEM₀₀ Nd:YVO₄ laser based on a semiconductor saturable absorber mirror (SESAM), with a high optical-to-optical conversion efficiency of 67.3%, and a slope efficiency of 71%. When the absorbed pump power was 11 W, 7.4 W average output power of 1064 nm continuous-wave mode-locked laser was achieved. To our knowledge, this is the highest optical-to-optical conversion efficiency among all the published reports of 880 nm LD pumped SESAM passive mode-locked lasers. The repetition rate of mode-locked pulse was 80 MHz with 26 ps pulse width. The maximum pulse energy and peak power were 92.5 nJ and 3.6 kW, respectively.     

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.     

GaN-based violet laser diodes grown on free-standing GaN substrate

A violet laser diode (LD) structure is grown on a free-standing c-plane GaN substrate and 4~μ m× 800~μ m ridge waveguide LDs are fabricated. The electrical and the optical characteristics of LDs under different facet-coating and chip-mounting conditions are investigated under pulse mode operation. The active region temperatures of p-side up and p-side down mounted LDs are calculated with different injection currents. The calculated thermal resistances of p-side up and p-side down mounted LDs are 4.6~K/W and 3~K/W, respectively. The threshold current of the p-side down mounted LD is much lower than that of the p-side up mounted LD. The blue shift of the emission wavelength with increasing injection current is observed only for the LD with p-side down mounting configuration, due to the more efficient heat dissipation.     

激光二极管抽运的Nd:YVO_4连续自拉曼1175nm激光器

报道了采用激光二极管端面抽运的Nd:YVO4晶体连续自拉曼激光器的实验研究.通过对晶体掺杂浓度及晶体结构的选择优化,减轻自拉曼晶体的热效应,实现了结构紧凑的1175 nm连续自拉曼激光器的高效运转.最终以两端键合的复合Nd:YVO4晶体作为自拉曼介质,在25.5 W的抽运功率下,获得了最高3.4 W的1175 nm连续拉曼光输出,光光转换效率为13.3%,拉曼阈值低至2.21 W,斜效率为14.6%.     

Efficient Nd:YVO_4 laser in-band pumped by wavelength-locked 913.9-nm laser diode and Q-switch operation

An efficient 1064-nm Nd:YVO_4laser in-band pumped by a wavelength-locked laser diode(LD) at 913.9 nm was demonstrated. The maximum continuous wave(CW) output power of 23.4 W at 1064 nm was realized with the incident pump power of 40 W, corresponding to a total optical-to-optical efficiency of 58.5%. This is to the best of our knowledge the highest total optical-to-optical efficiency and output power of Nd:YVO_4laser in-band pumped by a 913.9-nm laser diode.The Q-switched operation of this laser was also investigated. Through a contrast experiment of pumping at 808 nm, the experimental results showed that an Nd:YVO_4laser in-band pumped by a wavelength-locked LD at 913.9 nm had excellent pulse stability and beam quality for high repetition rate Q-switching operation.     

High power red-light GaInP/AlGaInP laser diodes with nonabsorbing windows based on Zn diffusion-induced quantum well intermixing

The layer structure of GaInP/AlGaInP quantum well laser diodes (LDs) was grown on GaAs substrate using low-pressure metalorganic chemical vapor deposition (LP-MOCVD) technique. In order to improve the catastrophic optical damage (COD) level of devices, a nonabsorbing window (NAW), which was based on Zn diffusion-induced quantum well intermixing, was fabricated near the both ends of the cavities. Zndiffusions were respectively carried out at 480, 500, 520, 540, and 580 ℃ for 20 minutes. The largest energy blue shift of 189.1 meV was observed in the window regions at 580 ℃. When the blue shift was 24.7 meV at 480 ℃, the COD power for the window LD was 86.7% higher than the conventional LD.     

LD泵浦高功率高斜效率Nd:YVO4声光调Q激光器

 报道了采用激光二极管(LD)端面泵浦Nd:YVO₄双端键合晶体高平均功率高斜效率1 064 nm声光调Q激光器。通过对大功率泵浦情况下激光晶体热透镜效应进行分析和估算,优化了模式匹配及热稳腔结构参数,实现了稳定的高功率高斜效率准连续脉冲激光输出。在泵浦功率46.8 W、最高重复频率50 kHz下,获得最大平均输出功率17.6 W,光-光转换效率为37.6%,斜效率达70.1%,脉冲宽度51.3 ns;在最低重复频率10 kHz下,获得最大单脉冲能量0.91 mJ,峰值功率为46.2 kW,脉冲宽度为19.8 ns。     

LD泵浦的高效掺钕钒酸钇(Nd3+:YVO4)激光器

本文报道了LD泵浦掺钕钒酸钇(Nd³⁺:YVO₄)激光器的实验结果.采用普通平一平腔结构,在10.6W泵浦功率时,得到4.95W激光输出,相应的斜率效率为53.8%;在另外一种情况下,得到了高达55.68%的斜率效率.并对实验结果进行了分析。     

All-fiber clad-pumped Tm3+-doped fiber amplifier using high power fiber combiner

The diode laser (LD) clad-pumped 1947.6 nm continuous wave (CW) Tm³⁺-doped fiber amplifier is reported using the master oscillation power amplifier (MOPA) method. The injected seed laser is provided by an all-fiber LD-clad-pumped Tm³⁺-doped single-mode fiber laser, which has a nearly 2.4 W maximal output power and 0.1 nm ultra-narrow linewidth based on the intracore reflection FBG. Using the 25/400 μm double-clad LMA Tm³⁺-doped fiber as the gain fiber, the output maximal output power is 30.6 W from the fiber amplifier, with a slope efficiency of 39.1% respected to the LD total output power. A high power multi-mode fiber combiner is used to couple high power LD light into the gain fiber. The output wavelength is also located at 1947.6 nm, with the slightly expanded laser linewidth of 0.2 nm.     

激光二极管侧面泵浦高功率266 nm紫外激光器

 报道了一种半导体激光列阵侧面泵浦Nd：YAG四倍频266 nm全固态紫外激光器,采用Z型腔结构,Ⅰ类临界相位匹配LBO和BBO晶体分别作为二倍频晶体和四倍频晶体。在调制频率为5 kHz时,最终获得了2.1 W的266 nm紫外激光输出,单脉冲能量420 μJ, 绿光到紫外激光的转换率为13.13%,在相同的泵浦功率下利用V型腔结构仅获得305 mW的266 nm紫外激光输出。