共查询到20条相似文献,搜索用时 62 毫秒
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用波长为532 nm、脉冲宽度为5 ns的超短激光脉冲触发电极间隙为4 mm的半绝缘GaAs光电导开关,开关偏置电压从500 V开始以步长50 V逐渐增加,直到开关出现非线性电脉冲输出.研究表明,线性和非线性电脉冲波形均呈现出在经历一个主脉冲之后,其后跟随几个幅值较小且具有周期性和不同程度的减幅振荡.分析了开关体内载流子(热电子)的微观状态和输运过程,在直流偏置电场作用下,开关体内的热电子在电子-电子、电子-声子相互作用过程中,当它们的弛豫时间大于载流子的寿命时, 光电子的输运可通过迁移率变化引起光电导振荡, 这是开关输出电脉冲出现振荡的原因.
关键词:
光电导开关
热电子
弛豫
光电导振荡 相似文献
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在飞秒激光激励下用GaAs光电导开关作为太赫兹(THz)辐射天线, 已经广泛用于太赫兹时域光谱系统, 但目前国际上都是使用GaAs光电导开关的线性工作模式, 而GaAs光电导开关的雪崩倍增工作模式所输出的超快电脉冲功率容量远大于其线性工作模式, 迄今为止, 还没有人提出用雪崩倍增机理的GaAs 光电导开关作为辐射源产生THz电磁辐射. 本文探讨了用 雪崩倍增工作模式的GaAs光电导开关作为光电导天线产生THz电磁波的可能性及研究进展. 通过理论分析及实验研究, 在实验上实现了: 1) 利用nJ量级飞秒激光触发GaAs光电导天线, 可以进入雪崩倍增工作模式; 2) 利用光激发电荷畴的猝灭模式, 可以使GaAs光电导天线载流子雪崩倍增模式的延续时间(lock-on 时间)变短. 这为利用具有雪崩倍增机理的GaAs光电导天线产生强THz辐射奠定了基础. 相似文献
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研制了耐压达32 kV,通态峰值电流达3.7 kA的高压超大电流半绝缘GaAs光电导开关.分析了光电导开关在强场下的击穿机理,指出对于间接能带间隙光导材料(如Si)制作的光电导开关,开关的击穿电压主要由陷阱填充限制电导模型决定.而对于直接能带间隙光导材料(如GaAs,InP等)制作的光电导开关,开关击穿主要是由开关体负阻效应在开关阳极产生的空间电荷累积所导致的开关阳极电场剧增引起的.基于转移电子效应对GaAs光电导开关击穿电压进行了理论计算,计算结果与实验相一致.
关键词:
光电导开关
击穿
转移电子效应
陷阱填充 相似文献
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有机高分子光折变材料的研究进展 总被引:3,自引:0,他引:3
基于有机高分子材料独特的化学和物理性质,阐明了发展有机高分子光折变材料的重要意义。通过对有机高分子材料的光电导和电光效应的分析,讨论了有机高分子材料成为高性能光折变材料的可能性。着重介绍了有机高分子光折变材料的化学结构和光折变性能。同时,简单分析了有机高分子光折变材料的研究现状以及当前存在的一些问题。 相似文献
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ZnS:Mn.Cu粉末直流电致发光(DCEL)屏的光电导特性 总被引:1,自引:1,他引:0
本文首次研究了DCEL屏的光电导特性,结果表明,Zn:Mn.Cu粉末DCEL屏的光电导特性主要是由于DCEL屏形成过程中,因Cu+离子迁移而在发光区(或乏铜区)的ZnS颗粒表面形成的表面电子陷阱能级被激发所致。 相似文献
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The effect of double frequency oftrap field φ = U - V1 cos Ωt - V2 cos 2Ωt in a Paul trap can be described exactly by using a function series expansion to solve the corresponding Mathieu equation.The stability regions of a trapped ion are plotted and some meaningful physical results are shown.`` 相似文献
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We have carried out a molecular dynamics stimulation for a few Paul-trapped ions exerted by a trapping force, inter-ion Coulomb forces and a damping force from a cooling source. The geometric structure in the ordered phase is studied in detail. It is found that the structure varies regularly with the ion number and forms concentric shells when the ion number grows. Furthermore, the similarity between the ions' structure and the potential of the trap is also presented. Finally, the case in the second stability region is investigated, which gives a comparison with that in the first stability region. 相似文献
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We have studied the ground state configurations of a rotating Bose-Einstein condensation in a toroidal trap as the radius of the central Gaussian potential expands adiabatically. Firstly, we observe that the vortices are devoured successively into the central hole of the condensate to form a giant vortex as the radius of the trap expands. When all the pre-existing vortices are absorbed, the angular momentum of the system still increase as the radius of the
gaussian potential enlarges. When increasing the interaction strength, we find that more singly quantized vortices are squeezed into the condensate, but the giant vortex does not change. 相似文献
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Inrecentexperimentsonlasercoolingandtrappingtheobservationofquantumefectsrelatedtotheatomiccentreofmasmotion(CM)hasbeenrepo... 相似文献
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The resonant transition in the Paul trap is studied by the time-space transformation and function series expansion. A new selection rule for the transition in the trap is derived strictly. Tlte probability in the ground state and solrle transition rates to the excited states are calculated. Tlte comparison with the former studies shotvs that our results are more accurate and credible. 相似文献
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We study Bose-Einstein condensation in a linear trap with a dimple potential where we model dimple potentials by Dirac δ function. Attractive and repulsive dimple potentials are taken into account. This model allows simple, explicit numerical and analytical investigations of noninteracting gases. Thus, the Schrdinger equation is used instead of the Gross-Pitaevski equation. We calculate the atomic density, the chemical potential, the critical temperature and the condensate fraction. The role of the relative depth of the dimple potential with respect to the linear trap in large condensate formation at enhanced temperatures is clearly revealed. Moreover, we also present a semi-classical method for calculating various quantities such as entropy analytically. Moreover, we compare the results of this paper with the results of a previous paper in which the harmonic trap with a dimple potential in 1D is investigated. 相似文献