基于单壁碳纳米管调Q锁模低阈值Tm,Ho:LiLuF_4激光器

采用垂直生长法制作的单壁碳纳米管作为可饱和吸收体,结合特殊的低阈值谐振腔设计,首次在Tm,Ho:LiLuF_4全固态激光器中实现了低阈值自启动被动调Q锁模运转.以波长可调的掺钛蓝宝石固体激光器作为抽运源,选用1.5%,3%和5%的输出耦合镜,获得了出光阈值低至52,59和62mW的连续光输出.采用3%输出耦合镜,获得了阈值低至250mW的稳定调Q锁模脉冲输出,调Q包络的脉宽为2μs,调Q包络下锁模脉冲重复频率178.6MHz,最大输出功率154mW,最大的单脉冲能量为0.86nJ,调制深度接近100%.     

基于氧化石墨烯的瓦级调Q锁模Tm:LuAG激光器

在Tm:LuAG全固态激光器中实现了以氧化石墨烯可饱和吸收体为锁模启动元件的瓦级被动调Q锁模运转.本实验装置以可调谐掺钛蓝宝石激光器作为泵浦源,测得Tm:LuAG固态激光器出光阈值最低为325mW,当吸收抽运功率达到3420 mW时,进入稳定的调Q锁模运行状态.当抽运功率达到8.1 W时,对应的最大输出功率为1740 mW,中心波长为2023 nm,重复频率为104.2 MHz,最大单脉冲能量为16.7 nJ,调制深度接近100%.     

Diode-pumped passively mode-locked Nd:YVO4 laser at 914 nm

We demonstrate, for the first time, to our knowledge, a diode-pumped passively mode-locked Nd:YVO4 laser, operating on the 4F(3/2)-4I(9/2) transition of the neodymium ion at 914 nm. We obtained 8.8 ps pulses at approximately 914 nm at a repetition rate of 94 MHz, and an averaged output power of 87 mW by using a semiconductor saturable absorber mirror.     

Développement de lasers visibles pompés par diode à base de cristaux de Nd:GdCOB autodoubleurs de fréquence

We present the performances of a diode-pumped solid-state laser operating in the visible by self-frequency-doubling. A cw output power of 115 mW at 545 nm has been obtained in a stable concave–concave cavity by using a crystal of Nd:GdCa₄O(BO₃)₃ pumped by a 2 W high-brightness laser diode. In a plano–plano cavity, similar to a microchip laser, we have obtained, for the first time to our knowledge, an output power of 22 mW in the green.     

Efficient 1 GHz Ti:sapphire laser with improved broadband continuum in the infrared

We demonstrate a 1 GHz prismless femtosecond Ti:sapphire ring laser that emits 890 mW for 7.6 W of pump power over a continuum extending from 585 to 1200 nm at -20 dB below the maximum. A broadband continuum is obtained with the net cavity group delay dispersion having -50 to 100 fs2 oscillations from 700 to 900 nm. Further broadening is obtained by use of a slightly convex cavity mirror that increases self-phase modulation. Approximately 17% (75%) of the intracavity (output) power is generated in single pass through the crystal, outside the cavity bandwidth, and concentrated in the low-gain IR from 960 to 1200 nm.     

Achieving single-lobed far-field patterns of broad area laser diode with external cavity feedback

We demonstrate a technique for single transverse mode operation of high-power broad area laser diode (BAL). In the experiment, the HR mirror is used as an external cavity mirror and the grating is used as a wavelength selective component. By tiling the HR mirror and the grating, the number of transverse modes oscillating in the cavity can be limited and the spectral bandwidth of the laser diode can be reduced. A single-lobed near diffraction-limited laser beam with the beam divergence (FWHM) of 0.43°, the spectral line-width of 0.7 nm and the output power of 350 mW are obtained. With the feedback, the power density of the output laser beam is increased 6 times in comparison with the free running.     

A Bidirectional, Diode-Pumped, Passively Mode-Locked Nd：YVO4 Ring Laser with a Low-Temperature-Grown Semiconductor Saturable Absorber Mirror

We report the operation of a bidirectional picosecond pulsed ring Nd：YVO4 laser based on a low-temperaturegrown semiconductor saturable absorber mirror. Except for the laser crystal, the six-mirror ring laser cavity has no intra-cavity elements such as focusing lens or mirror. The bidirectional mode locked pluses are obtained at the repetition rate of 117.5 MHz, pulse duration of 81 ps, power of 2 × 200 mW.     

自调Q、自锁模铒/镱共掺光纤激光器

研究了结构新颖的环形腔铒/镱（Er/Yb）共掺双包层光纤激光器.为了获得高功率激光输出,使用6个激光二极管（LD）同时抽运Er/Yb共掺光纤,采用光纤光栅（FBG）Sagnac环作为波长选择器,得到了中心波长为1548.11 nm、谱线宽度为0.06 nm的窄线宽激光输出;并利用增益光纤作为可饱和吸收体,实现了自调Q、自锁模脉冲输出.当抽运功率为719 mW时,激光器输出自调Q脉冲,脉冲周期为20μs,脉冲宽度为2.8μs,脉冲的平均功率为38.4mW,峰值功率为274.3mW;当抽运功率为3.6 W时,激光器输出自锁模脉冲,脉冲宽度为4ns,平均功率为319 mW,脉冲峰值功率大于10 W,重复频率为7.937 MHz.     

自锁模Cr:LiSAF激光器的特性研究

本文分析上转换过程及荧光热猝灭效应对Cr:LiSAF激光器的泵浦阈值和输出功率的影响,由此得出Cr:LiSAF激光器特别适合低功率泵浦.分析了三镜腔结构的特性,选择了腔的较佳参数,实现了在750mW的氩离子激光泵浦下三镜腔Cr:LiSAF激光器的自锁模运转.     

LD泵浦全固态608.1nm和频激光器

本文报道了一种全固态腔内和频608.1 nm激光器。在激光谐振腔两个分臂中,两支激光二极管分别泵浦Nd: YVO₄和Nd: YAG晶体,分别选择1 342 nm波长(Nd: YVO₄晶体的⁴F_3/2-⁴I_13/2谱线)与1 112 nm波长(Nd: YAG晶体的⁴F_3/2-⁴I_11/2谱线)振荡并进行腔内和频。通过优化谐振腔设计,腔内两个波长获得了较好的模式匹配。在两个分臂的交叠部分,利用LBO I类相位匹配进行和频,获得和频608.1 nm激光输出。实验表明,当Nd: YVO₄与Nd: YAG晶体泵浦功率分别为600和740 mW时,获得了功率为23.8 mW、波长为608.1 nm激光输出,激光输出稳定、噪声低。利用本文提出的和频结构是获得608.1 nm激光输出较为有效的方法。     

Passively mode locked femtosecond Tm:Sc2O3 laser at 2.1 μm

We report on the passive mode locking of a Tm3+:Sc2O3 laser at 2.1 μm using a semiconductor saturable absorber mirror based on InGaAsSb quantum wells. Transform-limited 218 fs pulses are generated with an average power of 210 mW. A maximum output power of 325 mW is produced during mode locking with the corresponding pulse duration of 246 fs at a pulse repetition frequency of 124.3 MHz. A Ti:sapphire laser is used as the pump source operating at 796 nm.     

Single-longitudinal-mode lasing of Tm,Ho:GdVO<Subscript>4</Subscript> using a filter of Fabry-Perot etalon and volume Bragg grating

In this letter, we report a diodepumped CW Tm, Ho:GdVO₄ laser at 77 K with a volume Bragg grating (VBG) instead of the conventional mirror. Inserting a Fabry-Perot etalon into the cavity, a singlelon-gitudinal-mode of Tm, Ho:GdVO₄ laser which I s operating at 2038.387 nm with output power 64 mW is obtained. The slope efficiency of 4.68% and a narrow linewidth about 45 pm FWHM are achieved. And appropriate cavity length is about 75 ± 5 mm.     

Diode-pumped passively Q-switched mode-locked Nd:LuVO4 laser with a semiconductor saturable absorber mirror

We present a compact passively Q-switched mode-locked Nd:LuVO₄ laser run in a Z-type folded cavity with semiconductor saturable absorber mirror (SESAM). The repetition rates of the passively Q-switched pulse envelope ranges from 22.99 to 141.18 kHz as the pump power increased from 2.372 to 8.960 W. The repetition rates of mode-locked laser pulses in the Q-switched pulse envelope has 111 MHz determined by the cavity length and the mode-locked pulse duration is evaluated to be 257 ps. An average output power of 823.5 mW is achieved at the pump power of 8.96 W, corresponding to an optical conversion efficiency of 9.2%.     

低阈值掺钛蓝宝石激光器实验研究

结合特殊的谐振腔设计和半导体可饱和吸收镜，建成了一台低阈值的自启动掺钛宝石激光器 . 分别用3％和12％的输出耦合镜，获得了阈值低至390mW和600mW的稳定锁模脉冲输出. 采 用12％输出耦合镜，在12W抽运时，输出平均功率为114mW，对应的典型脉宽为17fs，谱宽 为47nm. 相对于以往的低阈值克尔透镜锁模激光器，锁模工作的范围区域加宽，减小了操作 难度，提高了稳定性. 关键词： 低阈值 半导体可饱和吸收镜 克尔透镜锁模 掺钛蓝宝石激光器     

DESIGN OF A 532nm Nd:YVO4/KTP SINGLE-FREQUENCY LASER

A model of the laser-diode pumped solid-state laser is developed to deduce the minimum average radii of the pump beam in the solid medium, since the smaller the cavity waist, the higher the laser output power is expected to be. With an appropriate coupling system consisting of the collimating lens, prism pair and focusing lens, a diode-pumped single-frequency Nd:YVO₄/KTP intracavity frequency-doubling cw laser has been demonstrated through the precise temperature control of the Nd:YVO₄ crystal, the KTP crystal and the diode laser. The 532nm single-frequency output power of 40.4mW (in fact 55mW if the reflection loss of the triangular prism is taken into account) is obtained for an incident power of 515mW. It is derived theoretically and is verified in experiment that the frequency drift of the free-running laser can be reduced by increasing the cavity length.     

Passively mode-locked Nd：GdVO4 laser at 912nm

This paper demonstrates the passively mode-locked Nd：GdVO4 laser operating on the ^4F3/2-^4I9/2 transition at 912 nm by using a semiconductor saturable-absorber mirror for passive mode locking, stable continuous wave modelocked 912nm laser was achieved with a repetition rate of 176 MHz. At the incident pump power of 17.7W, 22.6mW average output power of stable mode-locked laser was obtained with a slope efficiency of 0.3%.     

Green Er(3+):YLiF(4) upconversion laser at 551nm with Yb(3+) codoping: a novel pumping scheme

We report room-temperature continuous-wave upconversion laser emission on the green transition (4)S(3/2)?(4)I(15/2) in Er(1%), Yb(3%):YLiF(4) at 551nm. Green laser operation was obtained for titanium-sapphire pump wavelengths continuously tunable between 955 and 974.5nm. Codoping with Yb(3+) resulted in a more efficient excitation of the upper laser level by upconversion processes. The maximum green laser output power was 37mW at an incident titanium-sapphire pump power level of 1580mW at 966nm.     

Diode-pumped femtosecond Yb:CaNb2O6 laser

We report to our knowledge a diode-pumped passively mode-locked Yb:CaNb(2)O(6) (Yb:CN) laser for the first time. Both CW and passive mode-locking operation of the laser are experimentally investigated. A maximum CW output power of 1.4 W with a slope efficiency of 20% is obtained on a 7 mm long 1.5 at.% Yb:CN crystal, while stable passive mode-locking with a commercial semiconductor saturable absorption mirror (SESAM) was achieved on a 3 mm long 3 at.% Yb:CN crystal. The mode-locked pulses have pulse width of 251 fs and an average output power of 44 mW at 1038 nm.     

Diode-pumped Pr(3+):KY(3)F(10) red laser

We report the first observation to our knowledge of room-temperature continuous-wave laser operation of a Pr(3+):KY(3)F(10) single crystal at 644.5 nm, pumped by a blue GaN laser diode emitting at 446 nm. With a 2.5% transmission output coupler and a nonoptimized optical cavity, an output power of 39 mW was obtained at 644.5 nm with a laser threshold of 125 mW and a differential slope efficiency of 23%.     

高重复频率1.34μm调Q锁模Nd:YVO_4激光器

报道了基于V:YAG可饱和吸收体的1.34μm被动调Q锁模Nd:YVO4激光器。采用直腔结构,使用透过率为10%的输出镜,在LD端面泵浦的情况下,实现了重复频率高达2.6GHz的1.34μm调Q锁模运转。Nd:YVO4晶体中,Nd3+离子掺杂质量分数为0.2%,V:YAG晶体的初始透过率为83%。在泵浦功率为11 W时,1.34μm调Q锁模激光的最大平均输出功率为308mW,光-光转换效率为2.8%。