紧凑型激光二极管端面抽运Nd:YVO4内腔三倍频355 nm紫外激光器

报道了一台激光二极管(LD)端面抽运Nd:YVO4晶体,利用两块LBO品体进行内腔二倍频和三倍频,实现了高效率、高峰值功率355 nm激光准连续输出的紧凑型全固态紫外激光器.激光腔采用简单平平直腔,腔长仅108 mm.当注入抽运功率6.76 W,重复频率20 kHz时,355 nm激光输出平均功率最高达245 mW,相应的光光转换效率为3.62%,脉冲宽度为8.0 ns,脉冲峰值功率为1.52 kW,输出功率短期不稳定性小于4.2%,光束质量良好.通过采用内腔倍频技术和设计合理的腔结构,整台激光器结构紧凑,体积小巧,便携性强,适合于中小功率紫外激光的输出,有利于进一步拓宽紫外激光器的应用领域.     

全固体激光器向离子激光器挑战

高功率连续波可见和紫外激光器的年销售市场约为7500万美元。其应用包括娱乐、科研激光器泵浦、医学、复印、立体光刻和光盘母盘刻录等方面。这种市场的规模和多样性吸收了众多激光器制造商提供各式各样的产品。直至最近，高功率连续波可见光和紫外激光器都还是“气体和离子激光器”的同义词。遗憾的是，目前水平的几瓦离子激光器其总体效率低于0．05％，这意味着“气体和离子激光器”具有很高电力和水力费用，以及高功率气体激光器所特有的大尺寸和大重量。虽然在绝对需要高功率（大于1W）、短波长（＜675mm）、高光束质量激光的应用中允…     

半导体泵浦固态紫外激光器在加工中的应用

激光器在工业加工中的应用越来越广泛,其中医疗器械的微加工、电子元件的封装、塑料的永久性冷标刻以及微型部件立体成型等应用的增长速度最快。以往,准分子激光器曾经是此类应用中主要的和首选的激光源。随着结构紧凑、具有高平均功率、高可靠性、操作简便的半导体泵浦固体紫外激光器的出现,情况又有了新的进展。实践证明,这种激光器不仅能够在某些应用领域中取代准分子激光器,而且它们的低操作成本和高可靠性等优点毫无疑问地将促进紫外微加工应用市场的飞跃和产品多样化的发展。紫外激加工的选捺紫外光的短波长对于微加工来讲有两个…     

铜激光器大步迈向新应用

较高功率、衍射极限光束质量及新的紫外波长使铜激光器可满足新市场 ,并降低成本。动力增强技术 ,将可见光功率增至原来的三倍 ( 1 0 0 W) ,这一功率的衍射极限光束适用于微加工。新倍频技术使利用高功率紫外光获得光纤布拉格光栅成为可能。再加上可靠性显著增强 ,使铜激光器走在工业和科研领域需求日益增长的市场。铜激光器同时运行在两个波长 5 1 0nm(绿光 )和 5 78nm(黄光 ) ,产生 2 0～ 5 0 ns短脉冲 ,高重复率时有良好的脉冲间稳定性。商品铜激光器单机输出功率可达 1 2 0 W,重复率 5 0 k Hz。通过振荡器 /放大器链可得到更高功率。…     

准分子激光技术的突破性进展

准分子激光技术的突破性进展经过二十年的发展，准分子激光器仍旧是功率最大的脉冲紫外激光器，它运用于金属和非金属材料的冷处理—消融，在材料上产生很清晰的边缘而不产生热效应。这种消融过程的特征来源于它很短的脉宽和十分高的峰值功率。与红外激光的基模相比，紫外...     

310 nm紫外固体拉曼激光器

利用偏硼酸钡（BBO）倍频晶体,实现了1064 nm激光泵浦金刚石拉曼激光器的高重复频率紫外激光脉冲输出。搭建了腔内倍频金刚石拉曼激光器,实现了620 nm激光输出。当1064 nm泵浦光的功率为4.0 W时,620 nm输出激光的功率为550 mW,转换效率约为13.7%。通过BBO晶体腔外倍频,获得了平均功率约为48 mW的310 nm紫外激光脉冲输出,脉冲重复频率为2 kHz,脉冲宽度约为761.8 ps,倍频效率约为8.7%。     

全固体化紫外激光技术

高输出功率紫外激光器在产业上主要用作超精细微加工光源而倍受关注。但市场上以往出售的高输出紫外激光器主要是准分子激光器,存在着装置大、工作效率低、使用腐蚀性气体、要更换气体、价格昂贵、维修成本高等缺点。因此,近几年市场要求开发能够解决上述问题的高输出全固体化紫外激光器。但是,几乎所有的固体激光波长都在近红外区,直接产生更短波长的激光非常困难。全固体化紫外激光器可将固体激光作为基波,通过波长转换成高次谐波生成紫外光。例如,为了从1064ｎｍ近红外光的Ｎｄ∶ＹＡＧ激光器得到紫外光,首先要产生二次谐波(波长532ｎｍ)…     

自由电子激光器的现状和应用

１引言 自由电子激光器可以工作在整个电磁谱区，并且正在迅速填补普通光源遗留下的光谱空白。自由电子激光器已经运转在微波至真空紫外区，平均功率达几千瓦，峰值功率达到千兆瓦。目前，自由电子激光器的发展方向是更高的平均功率和更短的波长。 自由电子激光器由电子束和它     

基于三硼酸锂晶体高功率紫外脉冲激光器

为了获得高功率、高重复频率的紫外脉冲激光器,采用1064nm基频光通过三硼酸锂（LBO）晶体与3次谐波355nm进行和频得到4次谐波266nm紫外激光的方法,进行了实验验证,取得了重复频率为20kHz、紫外激光器的平均输出功率为2.5W、红外到紫外的转换效率为12.5%的实验数据。结果表明,此脉冲激光器利用LBO晶体在高重复频率下取得了较大的紫外平均输出功率。     

高效率、高峰值功率351nm准连续紫外激光器

报道了一台高效率、高峰值功率351 nm紫外激光器。采用激光二极管（LD）端面抽运Nd:YLF晶体声光调Q获得准连续窄脉宽1 053 nm基波振荡,腔外两块LiB3O5（LBO）晶体紧贴输出镜放置,对基频光进行二倍频和三倍频,获得了高峰值功率351 nm紫外激光输出。在LD抽运功率为14 W、声光调 Q 激光器的调制频率为1 kHz的工作条件下,基波平均输出功率为1.45 W时,得到351 nm紫外激光平均输出功率450 mW,1 053 nm基频光到351 nm紫外光转换效率高达31.04%,脉冲宽度为7.5 ns,峰值功率达60 kW,光束质量良好。     

Hollow cathode metal ion lasers

A new class of metal ion lasers with significant CW output power in the UV (220-320 nm) and near IR (800-2000 nm) spectral regions is described. In a hollow cathode discharge the upper laser levels are excited via charge transfer collisions between ground state buffer gas ions and ground state metal atoms. At the present stage of development, hollow cathode metal ion lasers are shown to be comparable in UV output power to rare-gas ion lasers but with lower threshold currents by a factor of more than twenty. Visible output powers are lower than rare-gas ion lasers. In the text we present device progress to date, measurements of important plasma parameters, and an outline of potential applications of hollow cathode metal ion lasers.     

紫外铜离子激光器的理论研究

系统研究了连续工作的紫外铜离子激光器理论,即空心阴极放电的阴极位降理论,阴极溅射,放电等离子体中粒子的扩散和粒子数密度的速率方程。计算结果由实验得到验证。     

High-gain ultraviolet Cu-II laser in a segmented hollow cathodedischarge

We report measurements of the discharge and laser characteristics of an ultraviolet (UV) copper ion laser radiating on the 248.6- and 270.3-nm transitions. Our 50-cm active length laser operates in a high-voltage segmented hollow cathode discharge with Brewster windows and external mirrors. The lowest threshold currents were 7.3 and 5.6 A for the above transitions, respectively. The threshold current was found to increase with decreasing active length. We obtained superior gain characteristics (to 11.2 and 8.8%/m gain for the 248.6-and 270.3-nm transitions, respectively, at 0.3 A/cm linear current density) compared with previous studies on UV Cu ion lasers in conventional hollow cathode discharges     

Second-order DFB lasers fabricated by deep UV contact lithography and GSMBE

DFB ridge waveguide lasers at 1.55 mu m with uniform second-order gratings defined by deep UV lithography have been realised for the first time. The lasers have been fabricated using gas source molecular beam epitaxial (GSMBE) heterostructures grown in a two-step process. The characteristics of the DFB lasers (28 mA minimum threshold current, single-mode behaviour at output power in excess of 5 mW for more than 80% of the lasers and very low dispersion (+or-0.6 nm) of the lasing wavelength) demonstrate that deep UV lithography can be successfully used for the fabrication of DFB lasers.<>     

Novel tunable pulsed dye laser holography and subsequent processing for fabrication of optoelectronic device gratings

A tunable pulsed UV laser holographic system is described which has the capability for ease of fabrication of multiplexed laser arrays, chirped gratings and millimetre-long distributed feedback lasers. First-order optoelectronic gratings (periods of approximately 2500 ?) have been produced over the entire surface of 2 in (50.8 mm) InP substrate wafers. Diffraction efficiencies above 90% and grating depths of 1400 ? are reported.     

胆甾相液晶激光器研究进展

近年来国外学者对胆甾相液晶激光进行了大量研究,而国内在这方面研究甚少。介绍了胆甾相液晶周期性螺旋结构及其选择性反射特性,以及胆甾相液晶激光的工作原理,总结了胆甾相液晶激光的发展现状及其潜在的应用前景,以期为国内液晶研究的同行提供一点参考。     

A broadband helical saline water liquid antenna for wearable systems

A broadband helical liquid antenna made of saline water is proposed. A transparent hollow support is employed to fabricate the antenna. The rotation structure is fabricated with a thin flexible tube. The saline water with a concentration of 3.5% can be injected into or be extracted out from the tube to change the quantity of the solution. Thus, the tunability of the radiation pattern could be realised by applying the fluidity of the liquid. The radiation feature of the liquid antenna is compared with that of a metal one, and fairly good agreement has been achieved. Furthermore, three statements of the radiation performance corresponding to the ratio of the diameter to the wavelength of the helical saline water antenna have been proposed. It has been found that the resonance frequency increases when the length of the feeding probe or the radius of the vertical part of the liquid decreases. The fractional bandwidth can reach over 20% with a total height of 185 mm at 1.80 GHz. The measured results indicate reasonable approximation to the simulated. The characteristics of the liquid antenna make it a good candidate for various wireless applications, especially the wearable systems.     

High-frequency signal recording on film using (AlGa)As CW injection lasers

CW injection lasers have demonstrated excellent performance when used in a wide-band film recorder. These lasers have been internally modulated from 1 to 200 MHz (±2 dB) and film recordings of signal frequencies up to 100 MHz (160 cycles/mm) have been made.     

红外激光传输用聚苯乙烯—银—玻璃基体空心波导研究

利用液相镀膜法研制成了性能较好的传输用聚苯乙烯－银－玻璃基体小直径空心波导,波导长度达到1m左右,波导直径为800－1200μm,对于CO2激光（10.6μm）的传输损耗低达1.73dB/m,损伤阈值高于11.2W(17.2W/mm^2)。实验结果表明,聚苯乙烯－银－玻璃基体小直径空心波导适用于医学等领域CO2激光传输的要求,并有望在其他红外波段的激光能量传输中得到应用。     

新型红外激光功率合成器

利用矩形空心金属软波导和矩形变截面耦合器所构成的功率合成器,实现了两束CO_2激光的功率合成。实验中获得的传输效率为72.1％,合成光功率为31瓦。