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1.
Y. P. Zhao Y. Xie Q. Wang T. Liu 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,49(3):379-382
With pure Ar and gaseous mixtures of Ar-He, the laser spike of Ne-like Ar 46.9 nm pumped by capillary discharge is measured
with XRD (X-ray diode) at low pressure. We observe the effects of the Ar pressure and the He ratio on the amplitude of laser
pulse. Compared with the laser spike of pure Ar, a mixture of Ar and a small quantity of He enhances the laser output. The
time of lasing onset and the duration of laser pulses are not affected by mixing He. In addition, a monochromator is used
to measure the laser pulse at 46.9 nm. This is the first observation of laser output with a Ar-He mixture. 相似文献
2.
在一台毛细管快放电软x射线激光实验装置上,在相同主脉冲条件下(电流峰值18—30kA,半周期80ns),通过观测放电产生的软x射线辐射,研究了该装置固有的高幅值(2—5kA)和外加的低幅值(10—20A)两种预脉冲,对聚乙烯毛细管和高纯度陶瓷毛细管(99.9%)放电的管壁烧蚀及等离子体状态的影响.采用装置固有的几kA预脉冲和聚乙烯毛细管,放电 过程中产生了大量的管壁烧蚀,并且这种情况下的等离子体均匀性差,没有可能获得激光输 出.而采用20A的预脉冲和高纯度陶瓷毛细管,管壁烧蚀量大大减少,预电离等离子体的均匀 性好,在这种情况下,实验上利用x射线二极管观测到了激光尖峰信号.
关键词:
预脉冲
毛细管放电
软x射线激光 相似文献
3.
A New Discharge Scheme of a Prepulse Plus Two Main Pulses for Capillary-Discharge Soft-X-Ray Laser 下载免费PDF全文
Reducing the capillary-discharge current is one way of possibly decreasing the pumping power requirement. We examine the influence of various discharge currents on laser intensity and determine the suitable pre-discharge condition for a 46.9-nm discharge-pumped Ne-like Ar soft-x-ray amplifier. The experimental results show that a high additional pre-pulse current at amplitude of several kA and with a very short duration of several tens of nanosecond can effectively decrease the amplitude of the main discharge current at the lasing time. We propose a new discharge scheme of a pre~pulse plus two main pulses which appears to significantly decrease the requirement for discharge current. This in turn may decrease the pumping power requirement for the capillary discharge laser and can greatly increase laser efficiency. 相似文献
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利用x射线二极管(XRD),实验上测量了毛细管放电激励下类氖氩469nm软x射线激光的尖 峰信号. 改变毛细管的充气气压和主脉冲放电电流,研究了激光尖峰的产生时间随实验参数 的变化情况. 实验结果表明,激光产生于主脉冲电流波形的前沿,此时的主脉冲电流是其峰 值的65%—75%. 增加毛细管充气气压或者减小主脉冲峰值电流,激光的产生时间将会稍有延 迟. 同时改变毛细管充气气压时,激光尖峰信号在42Pa存在最大值.
关键词:
毛细管放电
软x射线激光
激光产生时间 相似文献
5.
S. Barnwal Y. B. S. R. Prasad S. Nigam K. Aneesh M. L. Sharma R. P. Kushwaha P. K. Tripathi P. A. Naik J. A. Chakera C. P. Navathe P. D. Gupta 《Applied physics. B, Lasers and optics》2014,117(1):131-139
Intense lasing had been obtained from argon plasma in the soft X-ray region from a capillary discharge plasma system. Different diagnostics have been used to characterize the lasing properties by recording the temporal, spatial, and spectral profiles of the emission. The divergence measurement indicates that the soft X-ray laser beam has good directionality with a divergence of 3.5 mrad. The spectrum of the laser beam measured using a transmission grating showed intense lasing line at 46.9 nm. Diffraction orders as high as 10th orders were observed. The temporal profile recorded with a vacuum diode showed a distinct laser peak with a pulse width ~1.2 ns (FWHM). In addition, the coherence of the X-ray laser beam was also confirmed from the high-contrast interference fringes (visibility ~85 %) recorded using double slits. 相似文献
6.
A. Ritucci G. Tomassetti A. Reale L. Palladino L. Reale T. Limongi F. Flora L. Mezi S.V. Khuklevsky A. Faenov T. Pikuz J. Kaiser 《等离子体物理论文集》2003,43(2):88-93
A capillary discharge pumped soft x‐ray laser operating at 46.9 nm on the 3p–3s transition of the Ne‐like Ar has been realized by pumping the active medium with a relatively slow current pulse (dI/dt ≈ 6 · 1011 A/s). In order to study the role of the ablation in the production of the laser effect, the intensity of the amplified 46.9 nm line has been investigated using the same pumping current pulses in the plastic (polyacetal) and ceramic (Al2O3). We showed that the ablation of the capillary walls is unfavorable both for the compression and stability of the plasma and consequently for the soft x‐ray laser production. The amplification and lasing effects are observed only in the ceramic channel. The measurements of the line intensity at 46.9 nm showed the lasing with a gain‐length product of ≈ 9, a laser pulse energy of ≈ 5 μJ, a pulse duration of 1.3 ns and a beam divergence of ≈ 3.5 mrad. In addition, effect of the scaling of the time of lasing with the initial plasma diameter was demonstrated experimentally and compared with a one‐dimensional MHD model. 相似文献
7.
Capillary discharge soft X-ray laser, which is always called “table-top soft X-ray laser,” is one of the effective methods for miniaturization. The method is deemed to have experimental facility with practicable value. With capillary discharge mechanism, Ne-like Ar at 46.9 nm soft X-ray laser has been obtained, and the experimental results and the analyses are reported in this paper. Experimentally, a current pulse with the amplitude of 20 kA was used to excite three different gases: Ar, Kr, and N2. The signals were detected by an X-ray diode (XRD), and the emission spectra were monitored with a Rowland spectrograph. The J = 0–1 line and one 3d-3p transition of Ne-like Ar were detected, with wavelengths of 46.9 nm and 48.5 nm, respectively. Adjusting the pure Ar to the appropriate pressure, the authors found that the J = 0–1 line gains amplification, while 3d-3p does not. When the Ar pressure was 26 Pa, the J = 0–1 line completely dominated the spectrum. N2 and Kr were used as the materials of capillary discharge respectively. The spike signal was obtained by XRD, then the spectrum was detected by Rowland spectrograph, and the spectrum of Kr7+ was found. 相似文献
8.
《Comptes Rendus de l''Academie des Sciences Series IV Physics》2000,1(8):1065-1081
For many years, researchers have envisioned the development of compact high repetition rate tabletop soft X-ray lasers that could be routinely used in application in numerous disciplines. With demonstrated average powers of several mW and mJ-level pulse energy at 46.9 nm, capillary discharge-pumped lasers are the first compact lasers to reach this goal. In this paper we summarize the development status of high repetition rate tabletop soft X-ray lasers based on capillary discharge excitation, and give examples of their successful use in several applications. Results of the use of a capillary discharge pumped 46.9 nm laser in dense plasma interferometry, soft X-ray reflectometry for the determination of optical constants, and laser ablation are described. The observation of lasing at 53 nm line in Ne-like Cl with output pulse energy up to 10 μJ is also reported. 相似文献
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The conditions under which the influence of the discharge circuitry inductance on the efficiency of pulsed-periodic copper-vapor lasers is weak are determined. It is shown that for efficient pumping of the lasing transitions of Cu atom in these lasers it is advisable to form an excitation pulse having steep edges of the voltage applied to the discharge tube with the duration spanning the pumping period and termination of the lasing process providing, at the same time, the conditions for aperiodic behavior of the discharge during the excitation pulse. Such a pumping pulse can be formed due to a partial discharge of the storage capacitor in the laser discharge circuit. It is also shown that under such conditions of excitation the efficiency of copper-vapor laser (CVL) with respect to the energy pumped into the active element can reach 10%. 相似文献
12.
G. I. Ryabtsev T. V. Bezyazychnaya M. V. Bogdanovich A. V. Grigor’ev V. V. Kabanov Y. V. Lebiadok A. G. Ryabtsev M. A. Shchemelev 《Applied physics. B, Lasers and optics》2012,108(2):283-288
A model taking into account the up-conversion processes involving the upper laser level and the presence of the unpumped regions within the active element along with the lasing transitions has been developed for the passive Q-switched ytterbium?Cerbium glass laser which was transversally pumped by the laser diode arrays. The results of the simulation allow determining the working point providing the stable and long-term operation of the laser. The correctness of the proposed optimized model was experimentally proved by means of a comparative investigation of the utmost permissible output lasing characteristics. The maximum output lasing pulse energy up to 16.5 mJ with the pulse duration of 11.5?C16.0 ns at the wavelength of 1.535 ??m has been achieved with the rectangular active element for the length of 32 mm. 相似文献
13.
研究了基于半导体光放大器(SOA)和双段级联取样光纤光栅构成的新型结构多波长激光器.设 计了取样光纤光栅,计算了其反射谱,模拟了多波长激光器的输出光谱.基于自行制作的SOA 和取样光纤光栅,进行了多波长激光器的实验研究,得到了间隔为0.8nm、输出功率不平坦 度小于1.0dB的11个波长输出.理论和实验两个方面都可以验证:与基于普通取样光栅的多波 长方案相比,基于双段级联取样光栅的方案能改善输出谱平坦度,并可提高可激射波长数.
关键词:
半导体光放大器
取样光纤光栅
多波长激光器 相似文献
14.
Janulewicz KA Schnürer M Tümmler J Priebe G Risse E Nickles PV Greenberg B Levin M Pukhov A Mandelbaum P Zigler A 《Optics letters》2005,30(12):1572-1574
Investigations of plasma produced by a boron nitride capillary discharge irradiated with a guided 20-TW Ti: sapphire laser pulse at a peak intensity of 4 x 10(18) W/cm2 are presented. The guided laser radiation in the plasma channel generated He-like ions that, subject to suitable plasma temperature, recombined into Li-like nitrogen ions. Intense radiation at a wavelength of 24.77 nm was observed, indicating possible lasing at the 3d(5/2) - 2p(3/2) transition in Li-like nitrogen. 相似文献
15.
Keenan R Dunn J Patel PK Price DF Smith RF Shlyaptsev VN 《Physical review letters》2005,94(10):103901
We have demonstrated a 10 Hz Ni-like Mo x-ray laser operating at 18.9 nm with 150 mJ total pump energy by employing a novel pumping scheme. The grazing-incidence scheme is described, where a picosecond pulse is incident at a grazing angle to a Mo plasma column produced by a slab target irradiated by a 200 ps laser pulse. This scheme uses refraction of the short pulse at a predetermined electron density to increase absorption to pump a specific gain region. The higher coupling efficiency inherent to this scheme allows a reduction in the pump energy where 70 mJ long pulse energy and 80 mJ short pulse energy are sufficient to produce lasing at a 10 Hz repetition rate. Under these conditions and by optimizing the delay between the pulses, we achieve strong amplification and close to saturation for 4 mm long targets. 相似文献
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A self-consistent model of a self-sustained discharge XeCl laser (Ne/Xe/HCl mixture) with prepulse-mainpulse excitation and magnetic switching which leads to high efficiency operation is described. The validity of the model is confirmed by comparing the results of the calculations with the measured time dependences of discharge voltage, current and lasing pulse for different operation modes as well as by comparing the results with the dependences of the laser output energy and efficiency on the charging voltage and capacitance of the pulse forming network for two different laser heads. The numerical evaluation has shown that our developed laser system operates under optimum conditions. 相似文献
19.
Adi Rahwanto Rintaro Nomura Norihiko Nishizawa Toshio Goto Masakazu Mori Kazuo Yamane 《Optical Review》1998,5(1):5-8
A new scheme of an amplitude modulated harmonically mode-locked Er-doped fiber ring laser is proposed, and the lasing characteristics are experimentally investigated. The transform-limited sech2 pulses at the repetition frequency of 1.64 GHz are stably generated. The pulse width and spectral bandwidth are independent of both the amplitude modulated (AM) modulation signal frequency and the AM modulation depth. 相似文献
20.
A copper-vapor laser the lasing medium of which is pumped by damped sine voltage pulses is studied experimentally. It is shown
that this laser can operate at megahertz lasing pulse repetition rates. Each current pulse in a train of damped sine excitation
pulses generates a lasing pulse. The time between lasing pulses is no more than 224 ns, which corresponds to a lasing pulse
repetition rate of more than 4.5 MHz. According to estimates, the use of the megahertz sine voltage to excite the copper-vapor
laser may raise the specific power of laser radiation by at least an order of magnitude at an efficiency of ≈15%. 相似文献