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1.
金属蒸气激光器是一类很有前途的新型激光器。它们的不断出现,使气体激光器的工作物质大大超出了周期表上的气体元素。据1978年为止的全面统计,作为气体及蒸气激光工作介质的元素现共达52种,其中金属蒸气占有36种以上;已得到的气体及蒸气的激光谱线共为5193条,其中金属蒸气的谱线有300余条。可见目前金属蒸气激光器在气体及蒸气激光器中的重要地位。  相似文献   

2.
釆用加热金属产生蒸气的方法,就能得到各种金属蒸气激光器。其中,铜蒸气激光器因具有高增益、高输出功率和产生高重复脉冲振荡等特点而引人注目。但是,为了从 金属铜得到激光器工作所需的蒸气压,必须把金属铜加热到1400~1500 ℃。  相似文献   

3.
尤里卡开发铜蒸气激光的应用钢蒸气激光器是现今可购到的最高功率可见光激光器,也是涉及六个国家20多个公司、研究所和大学的尤里卡计划的主题。为研究铜蒸气激光器在铜或铝精密打孔等方面的潜在应用(用其它激光器不可能在这种材料上打精密小孔),他们正在铜蒸气激光...  相似文献   

4.
总结了近几年来大口径、高功率铜蒸气激光器实验和理论方面的工作,讨论了高功率铜蒸气激光器结构、大口径铜节气激光器模型和工作物质的重大改进,展望了高功率铜节气激光器实验及理论方面的进展及可行性方案。  相似文献   

5.
100W铜蒸气激光器   总被引:3,自引:0,他引:3  
报告了高功率铜蒸气激光器研究的最新进展,给出了我们最近研制成的国内可见波段输出功率最大的100W铜蒸气激光器的一些主要技术参数。  相似文献   

6.
本文扼要介绍自限跃迁金属蒸气激光器的原理和特点,对国外铜原子蒸气激光器的研究概况、典型器件以及基本动力学过程作一评述。  相似文献   

7.
大口径铜蒸气激光器的研究   总被引:3,自引:0,他引:3  
研制成一台输出功率为百瓦级的铜蒸气激光器,其放电管长度为220cm,内径为6.5cm,脉冲重复频率为5kHz,最大输出功率为106W,效率为1%。给出了激光输出功率与放电参数的关系,通过与小口径(D<6cm)放电铜蒸气激光器比较,阐述了大口径铜蒸气激光器的一些物理特性  相似文献   

8.
英国牛津激光公司推销一种平均额定功率达60 W的锏蒸气激光器。这一额定值比其它商业铜蒸气激光器髙很多。新激光器在黄绿波段输出脉冲能量10 mJ或更多,脉冲重复频率在5~15 kHz之间。  相似文献   

9.
黄伟  谭荣清  李志永 《红外与激光工程》2016,45(2):206001-0206001(7)
基于三能级速率方程建立了横向泵浦铷蒸气激光器阈值计算模型,首次详细研究了横向泵浦铷蒸气激光器的泵浦阈值特性。论文结合实际参数,数值模拟了单Bar条半导体激光器横向泵浦铷蒸气的非线性吸收和泵浦光在蒸气室内的传播以及阈值工作状态下小信号增益的分布,仿真分析了蒸气室长度、温度、缓冲气体气压及组份配比、聚焦透镜焦距以及谐振腔诸参数对横向泵浦铷蒸气激光器出光阈值的影响。分析结果表明:对缓冲气体组份配比进行优化可以有效的降低泵浦阈值功率;蒸气室长度与温度共同影响阈值功率;较大的窗口片透过率和不大于70%的输出耦合率可以使泵浦阈值功率保持在较低的水平。文中对铷蒸气激光器等碱金属蒸气激光器的关键部件设计和系统优化可起到借鉴参考的作用。  相似文献   

10.
用以数字实验通用程序并以Бокс法和Гельфанд-цетлин法为依据的多因素输出参数最佳化算法为基础,提出了金属蒸气激光器最佳化的方法,得到了横向放电铜蒸气激光器三个参数的最佳化结果。  相似文献   

11.
A GaN vertical light emitting diode(LED)with a current block layer(CBL)was investigated.Vertical LEDs without a CBL,with a non-ohmic contact CBL and with a silicon dioxide CBL were fabricated.Optical and electrical tests were carried out.The results show that the light output power of vertical LEDs with a non-ohmic contact CBL and with a silicon dioxide CBL are 40.6%and 60.7%higher than that of vertical LEDs without a CBL at 350 mA,respectively.The efficiencies of vertical LEDs without a CBL,with a non-ohmic contact CBL and with a silicon dioxide CBL drop to 72%,78%and 85.5%of their maximum efficiency at 350 mA,respectively. Moreover,vertical LEDs with a non-ohmic contact CBL have relatively superior anti-electrostatic ability.  相似文献   

12.
本文对具有电流阻挡层(CBL)的氮化镓垂直结构发光二极管(LED)进行了研究。不带有CBL、带有非欧姆接触CBL和带有二氧化硅CBL的垂直LED芯片样品被制作出来,并对它们进行了光电性能的测试。结果表明这种带有非欧姆接触CBL和带有二氧化硅CBL的氮化镓垂直结构LED的光输出效率相比不带有CBL的分别高出40.6%和60.7%。不带有CBL的、带有非欧姆接触CBL和带有二氧化硅CBL的氮化镓垂直结构LED在350毫安下的效率分别下降到各自最高效率的72%、78%和85.5%。另外,带有非欧姆接触CBL的氮化镓垂直结构LED具有更优越的抗静电性能。  相似文献   

13.
The delay time of nanosecond electromagnetic pulses is measured in multiwalled carbon nanotube (MWCNT) bundles and copper wires, with a length of up to 3 cm, as compared with that in standard coaxial cables of the same lengths. Under certain configurations, when the Cu core of a coaxial cable is replaced with a MWCNT bundle of the same length, the measured delay time of a pulsed signal is shortened. The difference between the delay time measured for a device with a Cu core and that of a device with a MWCNT bundle of the same length increases with the length of the samples. The results imply that, compared with Cu wires, MWCNT bundles may be more efficient in guiding the transmission of high‐frequency signals along their longitudinal axis, showing a waveguide‐like effect.  相似文献   

14.
针对变形镜压电陶瓷类驱动器单元数多的特点,设计一种高带宽适合扩展成多通道输出的压电陶瓷驱动电源,它利用光耦分相隔离从源极驱动功率NMOS管,简化了电路结构并保证了功率带宽。该驱动电源驱动100 nF容性负载时,可实现单端到地-300~+300 V双极性高压输出,电压增益35.5 dB,信号不失真情况下,小信号响应频率达10 kHz,大信号响应频率2 kHz,瞬时充放电电流可达400 mA。实验表明该驱动电源的性能能够满足变形镜驱动的要求且电路结构简单。  相似文献   

15.
Time-differential perturbed angular correlations spectroscopy of palladium in doped germanium has identified palladium-vacancy pairing in n-type antimony-doped, p-type gallium-doped and undoped germanium. In contrast, an equivalent study of palladium defects in doped silicon suggests a different scenario for the silicon host. Palladium-vacancy pairing has been proposed in n-type silicon irrespective of the dopant type (phosphorous, arsenic or antimony) but palladium–boron pairing has been speculated to occur in p-type boron-doped silicon. This thus raises the question: why does palladium pair with a dopant atom in p-type silicon, but with a vacancy in p-type germanium? Based on the density functional theory calculations carried out in this work, it is suggested that the size of the dopant and the host material both play a crucial role in determining the type of palladium-defect complex that is formed. The calculations predict a configuration with the palladium atom on a bond-centered interstitial site pairing with a semi-vacancy on either side in gallium-doped and antimony-doped silicon and germanium, respectively. Whereas, a configuration with the palladium atom on a bond-centered interstitial site pairing with the dopant was proposed in boron-doped silicon and germanium. In further support of the argument, in n-type phosphorous-doped materials the calculations predict a configuration with the palladium atom on a bond-centered interstitial site pairing with a semi-vacancy on either side in silicon, but a configuration with the palladium atom on a bond-centered interstitial site pairing with the phosphorous dopant in germanium.  相似文献   

16.
一种结构新颖的微波高功率定向耦合器   总被引:2,自引:0,他引:2  
介绍一种结构新颖的微波高功率定向耦合器.该耦合器主线采用波导结构承受功率大,副线采用同轴结构对外连接方便,耦合机构采用单个圆孔实现,整个耦合器设计巧妙,结构简单,便于加工,易于装配,不用调试,指标好,可靠性高,特别适用于高功率、弱耦合、双向取样的场合.  相似文献   

17.
2D van der Waals magnetic semiconductors have emerged along with the possibilities of achieving an efficient gate tunability and a proximity effect with a high magnetic anisotropy compared with 3D counterparts. Little explored are multiple magnetic phases with a single crystallographic phase. Herein, the multiple magnetic phases in a Mn-doped SnS2 single crystal with different doping concentrations using a one-step self-flux method are reported. Two ferromagnetic phases with a canted spin direction exist regardless of the Mn-doping concentration at up to 5 at%. Antiferromagnetism coexists with the ferromagnetic order and strengthens at high Mn-doping concentrations. A magnetoresistance measurement conducted on a 2 at% Mn-SnS2 flake exhibits a positive-to-negative crossover with a value of as high as 50% and clear anisotropy, confirming the presence of ferromagnetic order in the material. By revealing multiple magnetic phases in Mn-doped SnS2, the study broadens the scope of state-of-the-art research on layered magnetic semiconductors.  相似文献   

18.
This paper addresses a fully‐integrated low phase noise X‐band oscillator fabricated using a carbon‐doped InGaP heterojunction bipolar transistor (HBT) GaAs process with a cutoff frequency of 53.2 GHz and maximum oscillation frequency of 70 GHz. The oscillator circuit consists of a negative resistance generating circuit with a base inductor, a resonating emitter circuit with a microstrip line, and a buffering resistive collector circuit with a tuning diode. The oscillator exhibits 4.33 dBm output power and achieves ?127.8 dBc/Hz phase noise at 100 kHz away from a 10.39 GHz oscillating frequency, which benchmarks the lowest reported phase noise achieved for a monolithic X‐band oscillator. The oscillator draws a 36 mA current from a 6.19 V supply with 47.1 MHz of frequency tuning range using a 4 V change. It occupies a 0.8 mm × 0.8 mm die area.  相似文献   

19.
This paper presents a hardware acceleration platform for image reconstruction in digital holographic imaging. The hardware accelerator executes a computationally demanding reconstruction algorithm which transforms an interference pattern captured on a digital image sensor into visible images. Focus in this work is to maximize computational efficiency, and to minimize the external memory transfer overhead, as well as required internal buffering. The paper presents an efficient processing datapath with a fast transpose unit and an interleaved memory storage scheme. The proposed architecture results in a speedup with a factor 3 compared with the traditional column/row approach for calculating the two-dimensional FFT. Memory sharing between the computational units reduces the on-chip memory requirements with over 50%. The custom hardware accelerator, extended with a microprocessor and a memory controller, has been implemented on a custom designed FPGA platform and integrated in a holographic microscope to reconstruct images. The proposed architecture targeting a 0.13 µm CMOS standard cell library achieves real-time image reconstruction with 20 frames per second.  相似文献   

20.
In this paper, a beam ID preamble (BIDP) technique, where a beam ID is transmitted in the physical layer, is proposed for efficient beam training in millimeter‐wave cellular communication systems. To facilitate beam ID detection in a multicell environment with multiple beams, a BIDP is designed such that a beam ID is mapped onto a Zadoff–Chu sequence in association with its cell ID. By analyzing the correlation property of the BIDP, it is shown that multiple beams can be transmitted simultaneously with the proposed technique with minimal interbeam interference in a multicell environment, where beams have different time delays due to propagation delay or multipath channel delay. Through simulation with a spatial channel model, it is shown that the best beam pairs can be found with a significantly reduced processing time of beam training in the proposed technique.  相似文献   

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