飞秒激光脉冲焊接透明微晶玻璃的实验研究

利用飞秒激光脉冲开展了零热膨胀系数Li2O-Al2O3-SiO2(LAS)透明微晶玻璃的非光学接触式焊接研究，分析了不同能量飞秒激光焊接LAS透明微晶玻璃的焊缝形貌和剪切强度，并对焊接后LAS透明微晶玻璃的透过率进行了测量。在激光脉冲宽度为300 fs、波长为1030 nm、单脉冲能量为3.0μJ时，焊接后LAS透明微晶玻璃的剪切强度高达23.51 MPa，光学透过率相对于原始LAS透明微晶玻璃下降了5%。随着单脉冲能量的增加，LAS透明微晶玻璃的光学透过率发生不同程度的下降，改性区域逐渐远离焦点，向激光源方向移动，使得分界面处的焊缝宽度先增大至10.7μm而后逐渐减小。X射线衍射分析结果表明，在该激光参数下实现了LAS透明微晶玻璃焊接而未产生新的晶相。     

空间三轴激光陀螺放电区微晶玻璃Li^(+)迁移规律研究EI北大核心CSCD

空间三轴激光陀螺是一种将三个敏感环路正交集成于一块微晶玻璃基体上的空间激光陀螺,在航空、航天、军事等领域得到了广泛应用。随着军用装备对高性能激光陀螺长期通电性能稳定性的要求不断提高,提高激光陀螺长期通电性能稳定性、延长激光陀螺工作寿命已成为国内外激光陀螺专业领域研究人员共同关注的重要课题。国外多项专利提到了微晶玻璃中的Li^(+)在电场的作用下发生迁移并影响激光陀螺工作寿命,但未见具体研究。文中对空间三轴激光陀螺开展了通电寿命试验,并结合飞行时间二次离子质谱分析技术,研究了放电区微晶玻璃LAS(Li_(2)O-Al_(2)O_(3)-SiO_(2))表面的Li^(+)迁移现象,结果表明:微晶玻璃中Li^(+)在激光陀螺电场及谐振腔内等离子体的作用下向谐振腔方向迁移,并脱离微晶玻璃进入谐振腔,然后随等离子体流动,最终沉积在阴极表面。该结果对提高激光陀螺长期通电性能稳定性、延长工作寿命等相关研究具有重要推进作用。     

微晶玻璃He-Ne激光管

根据影响 He-Ne 激光功率稳定性的因素,首次采用了透明微晶玻璃管作为外壳,可切削微晶玻璃作为反射镜调节头,管子为半外腔式同轴型结构。获得6328埃、1.15微米和3.39微米三种波长的激光输出,功率稳定性≤2%/2小时。     

氟磷酸盐玻璃的应用研究进展

氟磷酸盐玻璃系统南于其特殊的光学性能和优良的机做与热学性能一直是特种光学玻璃材料领域的一个研究热点。总结了氟磷酸盐玻璃的分类及玻璃组分与其结构的关系,综述了氟磷玻璃在光学器件、高能高功率激光玻璃、光纤激光器、光纤放大器及上转换发光基质材料等领域上的应用,并对其未来的发展进行了展望。     

钡镓锗透明微晶玻璃的制备及性能

文中通过微晶化工艺制备出钡镓锗透明微晶玻璃,并研究了其透红外性能和力学性能。结果表明,810~910℃热处理0.5 h 时,钡镓锗微晶玻璃析出单一ZrO2 晶体。处理温度为830℃时,钡镓锗微晶玻璃中开始析出少量ZrO2 晶粒,尺寸约几个纳米;处理温度升到870℃时,平均晶粒尺寸为250 nm;晶化温度高于870℃时,晶粒数量显著增多,晶粒粗大,而且发生团聚现象。晶化温度为810~850℃时,可以获得透红外性能和力学性能兼顾的钡镓锗透明微晶玻璃;处理温度为870℃时,钡镓锗微晶玻璃的力学性能出现极值,但透红外性能降低;若继续升高处理温度,钡镓锗微晶玻璃的透红外性能和力学性能均下降。     

用于光学微腔的玻璃微球研究进展

玻璃微球谐振腔具有极高的品质因数和极小的模式体积,近年来它在低阈值微球激光器、微放大器、非线性光学、腔量子电动力学效应以及高灵敏度传感器等领域引起广泛的关注。回顾了玻璃微球的研究历程,从玻璃微球制备方法、微球激光输出、耦合方式和传感器应用方面概括了玻璃微球的研究现状,对其发展前景进行了展望。     

光敏玻璃在飞秒激光作用下的析晶

采用高温熔融法制备了银掺杂的锂铝硅酸盐微晶玻璃.经近红外飞秒激光照射和热处理后,通过显微镜观察及X射线衍射分析发现,玻璃内部形成以银原子为晶核的Li2O·Al2O3·3SiO2多晶结构微晶,晶体细小,呈乳白色,为六方晶系,呈现空间取向分布结构.飞秒激光照射部位玻璃折射率发生明显变化,出现析晶;未照射部位折射率无明显变化,仍为玻璃体.利用光致折射率变化和飞秒激光的空间选择特性,可望在玻璃内部实现微光栅、波导、微机械器件、光学掩模等微结构.     

Eu3+掺杂CaO-MgO-SiO2透明微晶玻璃的制备及表征

采用熔融退火技术制备了CaO-MgO-SiO2:Eu3+基质玻璃,通过在不同热处理制度下使基质玻璃受控析晶制备了CaO-MgO-SiO2:Eu3+微晶玻璃。利用差热分析、X射线衍射(XRD)分析、扫描电子显微镜(SEM)以及荧光光谱等手段研究了透明微晶玻璃的热处理工艺、晶相组成和显微结构以及荧光性能,通过析晶动力学分析了基质玻璃的析晶机理,探讨了热处理制度同基质玻璃晶化以及显微结构之间的联系。掺杂Eu3+的玻璃和微晶玻璃样品,在394nm激发下观测到其5个发射峰分别位于在578(5 D0→7F0)、592(5 D0→7F1)、615(5 D0→7F2)、644(5 D0→7F3)和693nm(5 D0→7F4),Eu3+在微晶玻璃样品中的发射峰强度均大于基质玻璃。     

2×1组合式片状放大器增益特性实验研究

利用俄罗斯 2× 1× 3组合式片状放大器对国产N31新型磷酸盐激光玻璃和俄罗斯激光玻璃的增益特性进行了对比性实验研究 ,在相同的抽运条件下 ,得到了国产N31新型磷酸盐激光玻璃增益能力比俄罗斯激光玻璃高83 4%的实验结果。     

LD端抽运Er-Yb磷酸盐玻璃光波导放大器

总结了激光二极管(LD)端抽运Er-Yb磷酸盐玻璃光波导放大器方面所作的工作,内容涉及Er-Yb共掺磷酸盐激光玻璃材料、光波导放大器结构与特性等.由于这类放大器的优良性能与低的制作成本使得其在功率放大、在线放大、光无损分路器、光有线电视(CATV)系统及城域网等方面具有广阔的应用前景.     

Visible fiber lasers excited by GaN laser diodes

This paper describes and discusses visible fiber lasers that are excited by GaN laser diodes. One of the attractive points of visible light is that the human eye is sensitive to it between 400 and 700 nm, and therefore we can see applications in display technology. Of course, many other applications exist. First, we briefly review previously developed visible lasers in the gas, liquid, and solid-state phases and describe the history of primary solid-state visible laser research by focusing on rare-earth doped fluoride media, including glasses and crystals, to clarify the differences and the merits of primary solid-state visible lasers. We also demonstrate over 1 W operation of a Pr:WPFG fiber laser due to high-power GaN laser diodes and low-loss optical fibers (0.1 dB/m) made by waterproof fluoride glasses. This new optical fiber glass is based on an AlF₃ system fluoride glass, and its waterproof property is much better than the well known fluoride glass of ZBLAN.     

Glass lasers

In the eight years since the first publication of glass laser operation, considerable progress has been made in this technology with 5 active laser ions operating at 7 emission wavelengths having been confirmed so far. Laser action has been obtained in time regimes from continuous wave to pulsed operation with pulse widths down to 2.5 × 10^-13second. In addition, glass lasers currently provide the highest energy, the highest peak power, and the highest radiance laser sources. An efficiency of energy conversion to the optical second harmonic at 530 nm exceeding 50 percent has been obtained. Recent developments show promise of equaling gas laser performance in coherence length and average power. Present energy conversion efficiencies of over 8 percent and the development of a fiber laser receiver preamplifier are making glass laser systems applications increasingly attractive. This paper reviews the evolution of glass lasers, describes some recent developments, and discusses a number of applications in this fast-growing field.     

高功率激光系统中的小尺度自聚焦研究

概述了高功率激光系统中小尺度自聚焦产生的机理及相应的评价标准和分析方法,重点对激光经过钕玻璃介质和频率转换晶体的小尺度自聚焦情况进行了分析和讨论,同时介绍了两种测量小尺度调制增长的方法。针对高功率激光系统,阐述了抑制小尺度自聚焦的几种方法,提出通过控制小尺度调制增量,减少高功率激光的非线性效应对光学元件损伤的方案。指出了聚变级高功率激光技术中非线性效应研究的发展趋势。     

Passive mode locking of lasers with the optical Kerr effect modulator

A detailed analytical investigation is presented of a nonlinear device termed the optical Kerr effect modulator (OKEM) which is used to passivelyQswitch and mode lock high-power lasers. Experimentally, an OKEM employing two standard quarter-wave plates is used to passively mode lock the Nd:glass laser. The mode-locking threshold dependence upon the parameters of the OKEM transmission function is definitively established. Pulsewidths and spectral measurements are given for the train of ultrashort pulses from the glass laser mode locked with the OKEM using two different Kerr liquids. The analytical and experimental results together indicate that the OKEM technique is a versatile and viable alternative and in addition overcomes most of the shortcomings intrinsic to the saturable absorber technique. The non-resonant nature of the OKEM suggests that it should find immediate application as a passiveQ-switching and mode-locking element for a Variety of lasers, including dye lasers, UV lasers, the CO2laser, and, notably, the high-power iodine laser.     

4.6--Switching and control of a laser oscillator by injection of a giant-pulse laser signal

The switching and controlling of laser oscillation by optical injection or radiative-coupling schemes using the two laser system are investigated theoretically and experimentally in this paper. The output from aQ-switched laser was injected into the second laser to effect optical coupling. Corresponding to this model, we have succeeded in deriving a general analytical expression for the functional dependance of the quenching time interval on the parameters of the radiation-coupled lasers. The experimental results obtained using two ruby lasers compare quite favorably with the theoretical analysis. Finally, the preliminary observation of self-control or automodulation of laser oscillation due to optically induced ultrasonic vibration of the ruby rod through the optical coupling with the single laser pulse is mentioned briefly.     

光热折变玻璃的研究进展

光热折变玻璃是一种光敏硅酸盐玻璃,主成分为Na2O–ZnO–Al2O3–SiO2,并掺有Ag、Ce和F等成分,其折射率在紫外曝光并热处理后发生改变,具有在可见光以及红外光谱范围内损耗小,激光破坏阈值高,热稳定性好等特点,可用于制备衍射效率高,光谱选择性和角度选择性好的体Bragg光栅,可用于光谱窄化,相干耦合,谱合成等,在激光与光通信领域以及其他光学系统中有广阔的应用前景。分析了光热折变玻璃的折射率改变机制,讨论了光热折变玻璃的吸收特性,结构转变及激光破坏特性等光学特性。     

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。     

玻璃材料激光加工技术的研究进展

玻璃材料因其优良、独特的理化性能在半导体、微流控芯片、微机电系统、光通讯及光存储等新兴领域有广泛的应用.激光技术作为一种新型非接触加工方法,可以对玻璃材料表面或其内部进行高精度、高效率的微加工,在玻璃材料加工领域展现出巨大潜力.归纳了激光刻蚀、激光打孔、激光焊接及激光制备功能结构4种典型的激光加工玻璃工艺的基本原理及关...     

High repetition rate collisional soft X-ray lasers based on grazing incidence pumping

We discuss the demonstration of gain-saturated high repetition rate table-top soft X-ray lasers producing microwatt average powers at wavelengths ranging from 13.9 to 33 nm. The results were obtained heating a precreated plasma with a picosecond optical laser pulse impinging at grazing incidence onto a precreated plasma. This pumping geometry increases the energy deposition efficiency of the pump beam into the gain region, making it possible to saturate soft X-ray lasers in this wavelength range with a short pulse pump energy of only 1 J at 800-nm wavelength. Results corresponding to 5-Hz repetition rate operation of gain-saturated 14.7-nm Ni-like Pd and 32.6-nm line Ne-like Ti lasers pumped by a table-top Ti:sapphire laser are reported. We also discuss results obtained using a 1 /spl omega/1054-nm prepulse and 2 /spl omega/527-nm short pulse from a Nd:glass pump laser. This work demonstrates the feasibility of producing compact high average power soft X-ray lasers for applications.