1 / 32

V.A. Orlovich B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus,

NANA-2010 / 1. Stimulated Raman Scattering in Crystals as the Basic for Creating of New All-Solid-State Laser Systems 基于创建中的新型全固态激光系统的晶体中受激 Raman 散射. V.A. Orlovich B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Nezalezhnasti Ave. 68, 220072, Minsk, Belarus.

dana
Download Presentation

V.A. Orlovich B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus,

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. NANA-2010 / 1 Stimulated Raman Scattering in Crystals as the Basic for Creating of New All-Solid-State Laser Systems基于创建中的新型全固态激光系统的晶体中受激Raman散射 V.A.Orlovich B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Nezalezhnasti Ave. 68, 220072, Minsk, Belarus

  2. Content内容 NANA-2010 / 2 • Introduction: Stimulated Raman scattering as nonlinear optical effect 引言：SRC的非线性光学效果 • Diode-pumped lasers with intracavity Raman conversion 具有腔内Raman转换的二极管泵浦激光器 • Continuous-wave lasers连续波激光器 • Pulsed lasers 脉冲激光器 • Pulsed nanosecond laser systems with Raman convertors 有Raman装换装置的脉冲十亿分之一秒激光系统 • Continuously tunable laser systems 连续可调节式激光系统 • Pulsed NIR lasers 脉冲式NIR激光器 • Pulsed visible and UV lasers 脉冲式可见及远红外激光器 • Pulsed high average power and high repetition rate NIR lasers 脉冲式高均功率及高重复率NIR激光器 • Eye-safe pulsed laser systems 对眼安全的脉冲式激光系统 • Conclusion 结论

  3. differential cross section of the Raman transition Raman变换的微分交叉面 as L L S  as = L +  S = L -  Stokes scattering 斯托克斯散射 Anti-Stokes scattering 反斯托克斯散射 S  L S  L NANA-2010 / 3 Spontaneous Raman Scattering (Raman effect)自发性RAMAN散射（ RAMAN 作用） Raman scattering is inelastic process of light scattering. It involves in action the non-propagating collective modes of the substance. Raman散射是光散射的无弹性进程。它包括无扩展收集式 In the spontaneous regime of Raman scattering, the power of the Stokes and anti-Stokes waves is proportional to the power of the pumping wave.Raman斯托克斯散射和反斯托克斯散射波的功率与泵浦波功率成比例

  4. SRS arises at : Is≤ IL g – Raman gain coefficientRaman 增益系数 NANA-2010 / 4 StimulatedRamanScattering(I)受激Raman散射 At Stimulated Raman Scattering (SRS): • laser radiation power is > 1 kW; 激光放射能大于1kw • as a consequence the Stokes wave power increases;Stokes波功率增加的推论 • as a result : 结果 • the internal vibration mode of the medium is driven by the interference of the pump and Stokes waves; 媒介内部振动模式是由pump和stokes波干涉所驱动 • the Stokes wave is driven by the modulation of the pump wave by the material oscillations.物质震荡调节的pump波驱动stoke波

  5. traditional New SRS Femto- and attosecond pulse generation 飞秒以及阿托秒脉冲 Frequency Conversion 变频 traditional New traditional New New traditional Pulse Compression 脉冲压缩 Micro Raman lasers (50 μm-size) for microelectronics微电子器材的 微型Raman激光 Beam Combining 光线合成 Raman fiber lasersRaman纤维激光 Raman in solidsRaman在固体中 Raman solitons in communications通讯中的Raman孤立子 SRS: Field of Investigations 研究领域General Directions 总方向 NANA -2010 / 5

  6. NANA -2010 / 6 Directionsofinvestigations研究方向 • Measurement of nonlinear-optical parameters of Raman crystals and determination of its most perspective application areas (methods of the Raman amplification, z-scan). Raman水晶中非线性光学参数测量以及其最具可能的应用领域 • Elimination of the self- and cross interaction effects at SRS excitation with short (pico- and femtosecond) laser pulses. 用短激光脉冲激发SRS放射自己和相互作用 • Investigation of the physical processes in intracavity Raman conversion in end-diode pumped microchip and minilasers.终极二极管泵浦芯片及微激光在腔内Raman转换的物理过程的研究 • Investigation of the thermal effects in crystal Raman lasers 在晶体Raman激光中热效应的研究 • Development of methods of sharp reducing (up to ~ 103) of the Raman laser threshold. Raman激光临界的急剧减少(至~103)方法的发展 Results of our physical researches on the above directions will not be stated in the report. The main attention will be concentrated on Raman convertors and Raman lasers investigated by us. 上述方式的物理研究结果将不会在报告中陈述。我们主要致力于Raman转换器及Raman激光的研究

  7. NANA -2010 / 7 Diode-Pumped Lasers with Intracavity Raman Conversion 具有腔内Raman转换的二极管泵浦激光器 Continuous Wave (CW) Generation连续波生成 • Continuous wave (CW) lasers • are widely used in: 持续波激光广泛应用于： • atomic and molecular spectroscopy原子及分子光谱学 • medicine 医药 • environmental control 环境控制 • optical communications 光学通信 • instrumentation 仪表 At the time being only a small number of CW lasers generatingof few fixed frequencies or wavelength-tunable in the limited visible and infrared spectral ranges are available. 目前仅在少数的固定频率或又显得可见光和红外光谱范围的CW激光生成，是可用的 We have developed CW crystalline Raman lasers firstly in the world世界上我们首先开发的CW晶体Raman激光 • The theory of such lasers is presented in the following papers: • 该激光理论已经发表在下列论文中： • V.A. Lisinetskii, A.S. Grabtchikov, P.A. Apanasevich, M. Schmitt, B. Kuschner, • S. Schlucker, and V.A. Orlovich. J. Raman Spectr.37 (2006) 421 • 2. V.A. Lisinetskii, D.N. Busko, R.V. Chulkov, A.S. Grabtchikov, P.A. Apanasevich, • V.A. Orlovich. J. Appl. Spectroscopy 75 (2008) 284 • The results of our experiments are stated in the papers: • 我们的试验结果陈述在这些论文中： • Opt. Lett. 29 (2004) 2524; Opt. Lett. 30 (2005) 1701; Laser Phys. Lett. 3 (2006) 71; Appl. Phys. B 88 (2007) 499; Appl. Phys. B 86 (2007) 511.

  8. 1. Accumulation of Stokes radiation in independent Raman laser独立Raman激光中Stokes放射的积聚 Laser Laser Raman Raman Raman Stokes Raman Laser Stokes Stokes pump Stokes pump pump pump pump 2. Accumulation of pump and Stokes radiation at intracavity Raman conversion腔内Raman转换泵浦和Stokes放射的积聚 3. Accumulation of pump and Stokes radiation at intracavity self-frequency Raman conversion 腔内自频Raman转换中泵浦和stokes放射的积聚 4. Accumulation of pump and Stokes radiation at intracavity Raman conversion in composite crystals合成晶体中腔内Raman转换中的泵浦和Stokes放射的积聚 NANA -2010 / 8 Our approach for CW Raman laser我们的CW Raman激光研究方法 Using of Raman crystals - Hydrogen G  2.5 cm/GW; barium nitrate G = 48 cm/GW

  9. Nd:KGW or Nd:YVO4 crystals Stokes (1181 nm) Laser (1067 nm) fiber Cavity腔 Laser diode (808 nm) NANA -2010 / 9 Intracavity Raman self-frequency conversion in CW end-diode-pumped lasers在CW终极二极管泵浦激光内的腔内Raman自频率转换(optical scheme)光学计划 Raman self-frequency conversion implies that the processes of laser generation and Raman conversion occur in one and the samecrystalRaman 自频率频转换意味着产生激光和Raman转换在同一晶体中处理

  10. 1 Nd:YVO4 / YVO4 2 3 4 5 NANA -2010 / 10 Intracavity Raman self-frequency conversion at high power end-diode-pumping在高能终极二激光泵浦中的腔内Raman自频率转换 Points are experimental data. Solid lines are mathematical simulation data at the different intracavity losses (1 - 0.0032;2 - 0.0047;3 -0.0062 (the best approximation);4 - 0.0077;5 - 0.0091). Crystal length is 12 mm.点是试验数据。实心线条是在不同腔内损失的数学仿真。

  11. NANA -2010 / 11 Intracavity Raman self-frequency conversion and coherent mixingat high power end-diode-pumping在高功率终极二极管泵浦上腔内Raman自频转换和连贯混合 Stokes1176 nm Sum-mixing559 nm Fundamental1064 nm Beam profiles near the waist腰部附近的光线轮廓

  12. Diode pump Output Output mirror Input mirror Actively or passively Q-switched devices Gain medium Since 1987, much efforts were made to investigate and create diode pumped microchip lasers.自1987年，许多成就产生于二极管泵浦微芯片激光的研究和创造 NANA -2010 / 12 Diode-Pumped Pulsed Laserswith Intracavity Raman Conversion 具有腔内Raman转换的二极管泵浦脉冲式激光器 The microchip lasers with passive Q-switching can generate pulses with a duration from 0.2 ns to 8 ns and a peak power up to dozens of kilowatts有无源Q开关的微芯片激光器可以产生脉冲，其持续力可达0.2 ns 到 8 ns，高峰电流可达数千瓦 A typical cavity length is some millimeters.特有的腔长大约是几毫米 A single frequency mode of generation 产生单频率模式

  13. Actively or Passively Q-switched devices Raman medium Input mirror Gain medium Output mirror NANA -2010 / 13 Diode-Pumped Pulsed Laserswith Intracavity Raman Conversion The advantages of intracavity pulsed Raman conversion are:腔内脉冲式Raman转换的优点：- a low threshold of Raman excitation;激活Raman的低临界值- the possibility of the pump and Stokes pulse duration control (including pulse compression)泵浦及Stokes脉冲持续时间的可控制控制性（包括脉冲压缩） We have developed diode-pumped microchip- and mini-lasers with intracavity Raman conversion firstly in the world.我们首先在世界上开发了具有腔内Raman转换的二极管泵浦微芯片和微激光 Our main publications: Appl. Phys. Lett. 75 (1999) 3742; J. Alloys and Compounds 300-301(2000)300; Appl. Phys. B 19 (2002) 113; Apl. Phys. Lett. 81 (2002) 2926; Appl. Phys. B (2003); JOSA B 22 (2005) 2450; Opt. Comm. 263 (2006) 52; Opt. Comm. 281 (2008) 5202; JOSA B, 2010 (in press)

  14. Pp = 30kW Pp = 40kW 48.5 ps 221.8 ps a) b) NANA -2010 / 14 Diode-Pumped Pulsed Laserswith Intracavity Raman Conversion Typical oscillogramsof the output Stokes pulses from microchip laser with intracavity Raman conversion从腔内转换微芯片激光器输出Stokes脉冲的典型示波图 PP=8.9 W

  15. NANA -2010 / 15 Diode-Pumped Pulsed Lasers with Intracavity Raman conversion Additional nonlinear optical conversion(harmonic generation and sum-frequency mixing the radiation of microchip lasers)增加非线性光学转换（谐波产生及和频混合了微芯片激光器放射） The wavelengths of the generated radiation产生辐射的波长= 9407 cm-1; R = 8360 cm-1;  = 1047 cm-1

  16. NANA -2010 / 16 Pulsed nanosecond laser systems with Raman converters.Continuously tunable laser system具有Raman转换器的脉冲式十亿分之一秒激光系统 连续可调的激光系统 The system includes Nd:YAG laser, master oscillator - power amplifier (MOPA) Ti:Sapphire laser, LiF2- - laser, harmonic generators and Raman convertor on Ba(NO3)2 crystal (Opt. Commun. 218 (2003) 351; J.Raman Spectr. 31 (2000) 851).系统包括：Nd：YAG激光，主振荡器-功放，Ti：Sapphire激光，LiF2激光，谐波发生器，Raman转换器 在BaNO3)2晶体上 Master oscillator - power amplifier (MOPA) Ti:Sapphire laser system

  17. NANA -2010 / 17 Tuning curves调整曲线of MOPA Ti:Sapphire laser system (the fundamental, 2nd, 3rd, and 4th harmonics) for three different holographic selectors针对三个不同的全息分离器

  18. NANA -2010 / 18 Optical scheme and tuning curves of continuously tunable (187 - 1800 nm) pulsed laser system光计划和连续可调脉冲式激光系统的可调曲线（）

  19. NANA -2010 / 19 Pulsed High Energy NIR Raman Lasers脉冲式高能NIRRaman激光器 1st Stokes generation (1197 nm) We have developed a Raman laser generating at three Stokes lines with record values of pulse energy (Opt. Comm. 272 (2007) 509). The problem of suppression of generation at higher Stokes lines has been solved. 我们已经开发了在三条具有脉冲能量记录值的Stokes线的Raman激光生成。已经解决了在较高的Stokes线上生成的抑制问题。 Energy of 156 mJ is achieved Efficiency - 59% (quantum efficiency - 66%)

  20. NANA -2010 / 20 Pulsed High Energy NIR Raman lasers.3rd Stokes generation (1599 nm) OC3: HR at pump HR at 1st Stokes HR at 2nd Stokes R=35% at 3rd Stokes To generate 3rd Stokes the 4th Stokes should be suppressed. But in barium nitrate crystal there is an absorption at 4th Stokes wavelength. So there is no necessity for additional 4th Stokes suppression and the simple linear cavity can be used。 4thstokes压缩后可产生3rdstokes。但是在硝酸钡晶体中，4thstokes波长被吸收。因此没有必要做额外的4th stokes压缩，简单的线性腔就可以被使用 Energy of 116 mJ is achieved Efficiency - 42% (quantum efficiency - 63%)

  21. NANA -2010 / 21 Pulsed Visible and UV Raman lasers脉冲式可见和紫外线Raman激光器 To suppress the generation at 2nd Stokes line we have used three-mirror scheme for Raman laser cavity. Raman laser was based on Ba(NO3)2 crystal. 要压缩2nd stokes， 我们在Raman激光腔里用了三反射镜。Raman激光是以硝酸钡晶体为基础的  = 563 nm  = 281 nm Quantum efficiency - 70% This Raman laser with second harmonic generator is used in troposphere ozone lidar 此2谐波制造器的Raman激光被用作对流层臭氧激光雷达

  22. NANA -2010 / 22 Pulsed high average power and high repetition rate NIR lasers脉冲式高均功率和高重复率NIR激光器 Remote sensing of atmosphere by means of space-based lidars requires laser sources with high average power. We have developed a Raman laser with a record values of average power for a such application用宇宙用途的激光雷达来实现的宇宙遥控感知需要有高均功率的激光源。 我们开发了用于此研究的有记录值的高均功率的Raman激光 (V.A. Lisinetskii, T. Riesbeck, H. Rhee, H.J. Eichler, and V.A. Orlovich, “High average power generation in barium nitrate Raman laser ”, Applied Physics B, published online November 1, 2009). Repetition rate: ~1 kHz Pulse duration: ~40-50 ns (FWHM) Generation bands: 1 Stokes: 1.197 m 2 Stokes: 1.369 m 3 Stokes: 1.598 m Spectral bandwidth: 0.1-0.3 cm-1 Beam divergence: <5 mrad Beam quality factors: 1 Stokes: M2~3 2 Stokes: M2<2 3 Stokes: M2<5

  23. NANA -2010 / 23 Pulsed high average power and high repetition rate NIR lasers The dependences of average output power Pout and conversion efficiency Pout/ Pp on average pump power Pp 在平均泵浦功率上平均输出功率和转换效率的依赖性 1st Stokes line 2nd Stokes line 3rd Stokes line PMAX=17 W PMAX=9.5 W PMAX=5 W

  24. NANA -2010 / 24 Multiwave high repetition rate UV - NIR lasers多波高重复率UV-NIR激光器 Frequency doubling and coherent mixing of the radiation of the generated Stokes components is realized in BBO, LBO, and LiIO3 crystals to obtain the radiation in UV region. The radiation at 281.7, 290.3, 299.4, 309, 319.4, 330.4, 342.3, 368.7, 399.5, and 436 nm with average power from several mW to 20 mW has been generated.为了获得红外线区域的放射，我们实现了在BBO，LBO和LiIO3水晶中由不断倍化及持续混合已产生的stokes合成的放射。此放射在281.7, 290.3, 299.4, 309, 319.4, 330.4, 342.3, 368.7, 399.5, and 436 nm给以several mW to 20 mW 的均功率可以产生The studied laser system allows one to generate the quasi-CW radiation at 21 wavelengths in the range of 281 - 1600nm. Average power is varied from several mW to 1.2 W. Minimum spectral width of the radiation is equal to 0.2 cm-1.研究的激光系统考虑一个在21波长上281-16000nm范围内产生拟-CW辐射。平均功率从几个MW到1.2W不等。辐射的最小光谱宽度等于0.2cm

  25. NANA -2010 / 25 Eye-safe pulsed laser systems对眼安全的脉冲式激光系统 • Eye-safe lasers find wide application in environmental protection, laser range-finders, lidars used in built-up areas. • There are two main approaches to obtain generation in eye-safe spectral range:对眼安全激光器在环保，激光测距仪，用于建筑区域的激光雷达上有广泛的应用。有两个主要方法来获得对眼安全光谱范围内的生成。 • direct generation in crystals and glasses doped by erbium ions;在加入铒离子的晶体和玻璃里直接产生 • nonlinear optical conversion of radiation of lasers based on • neodymium-doped crystals.在加入钕的晶体中进行激光器放射的非线性光学转换 We have investigated in detail the second approach. At the beginning we used lasers with lamp pump in our experiments. At present we use side-diode-pumped lasers. Nonlinear optical conversion was being obtained by Stimulated Raman Scattering in crystals and Optical Parametric Oscillation. 我们主要对第二种方法进行研究。起初我们在试验中用带有lamp泵的激光。现在我们用二极管激光器侧泵激光器。 通过在晶体中的受激Raman散射及光参量振荡，我们得到了非线性光学转换。 Our results are published in the following papers: J. Opt. Technol. 67 (2000) 64; J. Appl. Spectr. 73 (2006) 254; J. Appl. Spectr. 73 (2006) 330; J. Appl. Spectr. 73 (2006) 535; J. Appl. Spectr.75 (2008) 516; J. Appl. Spectr. 76 (2009)499; J. Appl. Spectr. 76 (2009) 725; J. Appl. Spectr. 77 (2010) in press.

  26. Q-switch 1) 1.538 m (R =901.5 см-1 ) Nd:KGW Nd:KGW Nd:KGW 1St = 1.538 m Q-switch 2) 1.507 m (R =767.5 см-1 ) =1.351 m =1.351 m NANA -2010 / 26 Eye-safe pulsed laser systems based on Raman conversion基于Raman转换的对眼安全脉冲激光系统 We have used two approaches:我们使用了两种方法1. Laser generation was obtained in Nd:KGW crystal at work transition 4F3/2→4I13/2在Nd：KGW晶体里的转换工作中获得激光器生成。λ = 1.351 μm。a) this radiation excited SRS in laser crystal Nd:KGW (Raman self-frequency conversion) 该辐射激活在激光晶体Nd：KGW里的SRS（）。1.351 μm → 1.538 μm.b) this radiation excited SRS in additional Raman laser based on KGW crystal该辐射激活基于KGW晶体的附加Raman激光器里的SRS。1.351μm → 1.538 μm.

  27. 3St=1.5 m Nd:KGW Nd:KGW Q-switch =1.067 m 1.067 m 1.5 m 10 ns/div Oscilloscope traces of the primary laser radiation and of the pulse in the third Stokes component 初始激光放射的示波器和第三Stokes组件里的脉冲图形 Optical spectra around 1 and 1.5 m; the extreme positions of Raman line are shown.1和1.5um左右的光谱。显示了Raman线的末端位置 NANA -2010 / 27 Eye-safe pulsed laser systems based on Raman conversion Laser generation was obtained in Nd:KGW crystal at work transition 4F3/2→ 4I11/2 (λ = 1.067 μm).This radiation excited three Stokes lines in Nd:KGW crystal

  28. КТР- crystal- based OPO Multimode Nd-laser 1.06 m 1.57 m Behavior of eye-safe radiation energy for prolonged source operation at frequency10 Hz and histogram of relative frequencies hi= ni/nifor impingement of pulse energy Es in the i-th interval of 0.2 mJ; niis the number of OPO pulses in the i-th interval.针对在频率10Hz的长期源操作对眼安全辐射能量的性能相关频率的直方图hi= ni/ni对脉冲能量的影响，Es在0.2mJ的第i-th区间内，ni是OPO脉冲在第i区间数 Output energy of OPO at eye-safe wavelength ~1.57 µm as a function of electrical pumping energy of Nd:YAG laser and optical spectrum around 1.57 m OPO的输出能量在对眼安全波长~1.57 µm作为Nd:YAG激光的电泵浦能量的功能和光学频谱1.57 µm左右 NANA -2010 / 28 Eye-safe pulsed laser systems based on OPO

  29. NANA -2010 / 29 Types of eye-safe radiation sources and their main parameters 对眼安全辐射源的类型和它们的主要参数 type laser channelof conversion output radiation I. Nd3+:KGW(4F3/24I13/2 ): {SRS} I Stokes component II. Nd3+:KGW(4F3/2 4I11/2): {SRS} III Stokes component III. Nd3+:YAG(4F3/2 4I11/2): {OPO} signal wave Eye-safe radiation sources on the basis of nonlinear optical conversion of diode-pumped laser radiation are in a stage of investigations.在二极管泵浦激光辐射的非线性光转换的基础上对眼安全辐射源处于研究阶段。 The prospective laser parameters are: pulse rate – 10-20 Hz, pulse energy – 30-50 mJ. 未来的激光参数为：脉冲频率 - 10-20Hz，脉冲能量 - 30-50mJ。

  30. NANA -2010 / 30 Conclusion • Stimulated Raman Scattering in crystals is an efficient way for development laser systems generating the continuous wave radiation, as well as the pulse one with a pulse rate up to 100 kHz and a pulse width up to tens of femtoseconds;晶体中的受激Raman散射是开发连续波辐射生成激光系统的有效途径，以及一脉接一脉率高达100kHz和脉冲宽度达到几十飞秒； • 2. The efficiency of laser radiation conversion into a single line defined in advance is more than 50 %;在激光辐射转换成预先定义的单线的效率超过50％; • 3. Using intracavity Raman conversion it is possible to compress pulses at simultaneous increasing their peak power about ten times;使用内腔Raman转换有可能在同步压缩脉冲增加十倍左右的峰值功率 • 4. On the basis of SRS it is possible to develop simple and compact laser systems for different applications, including the systems generating in eye-safe spectral range.在SRS的基础上针对不同的应用，包括对眼安全光谱范围内生成系统，可以开发简单和复杂激光系统。

  31. NANA -2010 / 31 Our scientific group has a great experience in laser physics, nonlinear optics, laser spectroscopy, as well development of laser and optical systems for practical applications (environmental protection, medicine, scientific research et set ). 我们的科学团队在激光物理，非线性光学，激光光谱学等领域以及激光和光学实际应用（环境保护，医学，科学研究等等）系统的开发具有丰富的经验。

  32. NANA -2010 / 32 Our Scientific Group Thank you for attention !

More Related