共查询到18条相似文献,搜索用时 171 毫秒
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CO2激光成像雷达距离分辨率测距精度的分析与实验研究 总被引:5,自引:5,他引:0
分析了脉冲外差体制CO2激光成像雷达系统的目标距离分辨率、测距精度和误差的主要来源.对于单个光脉冲测距来讲,信噪比(SNR)起伏引起的探测误差、脉冲前沿触发等概率分布以及脉冲建立时间的随机性等是激光脉冲外差测距的主要随机误差,其它随机误差在数量级上可忽略不计.同时利用现有的CO2激光脉冲外差探测系统,进行了远目标测距对比实验,观测到了2355 m目标脉冲回波信号,并精确测量出CO2光脉冲飞行的往返时间,该实验数据可用做系统误差的校正和补偿. 相似文献
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用时域ABCD矩阵对调Q锁模激光器的研究 总被引:3,自引:3,他引:0
用时域ABCD矩阵讨论了调Q锁模脉冲激光器输出脉冲的宽度和啁啾特性,主要给出了调Q元件作为幅度调制元件时的时域ABCD矩阵,并将光脉冲在激光腔中往返一周的ABCD矩阵写出,用此矩阵讨论了它对锁模脉冲的影响.给出了Nd:YAG激光器中用Cr4+:YAG作调Q元件时的调Q锁模脉冲激光器特性,并讨论了腔内色散、饱和吸收强度、增益带宽对输出脉冲特性的影响.用时域ABCD矩阵大大简化了计算过程. 相似文献
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二极管泵浦被动调Q Nd:YAG/ KTP绿光激光器 总被引:1,自引:1,他引:0
报道了LD泵浦的Nd:YAG/KTP/Cr:YAG结构被动调Q绿光激光器.当注入泵浦功率为750mW时,获得了平均功率38mW,脉冲宽度14.7ns,重复频率20.4kHz,峰值功率126.6W的调Q绿激光输出. 相似文献
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从均匀场电极理论出发,计算并讨论了近似Rogowski电极、Chang电极(含紧凑式Chang电极)和Ernst电极的形状、理论电场分布和实际电场分布。对实验室所用的几种电极进行了脉冲放电实验,从而获得了TEA CO2激光器的放电参数与输出特性,并对这些结果进行了比较和分析。计算表明,在基本参数相同的情况下,Ernst电极具有最紧凑的外形和最佳的均匀电场分布。实验表明,采用近似Rogowski电极的TEA CO2激光器具有最大放电辉光范围和44 kV的最小放电击穿电压;采用Ernst电极的TEA CO2激光器具有25 J的最高单脉冲能量和最大17.2%的斜率效率。最后提出了TEA CO2激光器主电极的选择建议。 相似文献
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多模偶相干态光场中的N次方Y压缩与N次方H压缩特性研究 总被引:62,自引:39,他引:23
本文根据新近建立的多模辐射场的广义非线性等阶高阶压缩理论,对多模偶相干态光场冲|ψ,e〉q中的N次方Y压缩、N次方H压缩、N-Y最小测不准态以及N-H最小测不准态等进行了详细研究。结果表明:1)当N为偶数时,态|ψ,e〉q恒处于N-Y最小测不准态;当N为奇数时,态|ψ,e〉q在一定条件下存在着周期性变化的、任意阶的N次方Y压缩效应,2)当q·N为偶数时,态|ψ,e〉q恒处于N-H最小测不准态。当q·N为奇数时,在另外的条件下,态|ψ,e〉q存在着周期性变化的、任意阶的N次方H压缩效应。3)N次方Y压缩效应与N次方H压缩效应两者的压缩程度和深度均与几率幅yq(e)、压缩参数Rj、各模的初始相位ψj(或者初始相位和∑j=1qψj)、压缩阶数N及腔模总数q等非线性相关,后者与上述诸参量的非线性关联程度要比前者的更强。 相似文献
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从实验上证实Hg0.695Cd0.305Te 光电二极管空间电荷区中存在双光子吸收的Franz-Keldysh效应.利用一个皮秒Nd:YAG激光器抽运的光学参量产生器和差频产生器作为激发光源,测量了入射波长为λ0=7.92μm的脉冲激光所激发的光响应随入射光强的变化关系.脉冲光响应峰值强度随入射光强的增大呈现二次幂函数增强趋势.采用等效RC电路模型将脉冲光伏信号峰值与入射光强相关联,得到空间电荷区中强电场下单光束 相似文献
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一种新型的两态叠加多模Schrödinger猫态光场的等阶N次方Y压缩 总被引:3,自引:3,他引:0
本文根据量子力学的线性叠加原理,构造了由多模(即q模)相干态的相反态|{-Zj}〉q及多模虚相干态|{Zj}〉q这两者的线性叠加所组成的一种新型的多模Schrdinger猫态光场|Ψ(2)〉q,利用新近建立的多模压缩态理论,研究了态|Ψ(2)〉q的N次方Y压缩效应。结果发现:①当压缩阶数N=2p且p=2m(m=1,2,3,…,…)时,态|Ψ(2)〉q总是恒处于N-Y最小测不准态;②当压缩阶数N=2p且p=2m+1(m=0,1,2,3,…,…)时,如果各模的初始相位φj,态间的初始相位差θpq(I)-θnq(R)以及各单模相干态光场的平均光子数之总和
等满足一定的量子化条件,则态|Ψ(2)〉q可呈现出周期性变化的、任意阶的N次方Y压缩效应;③当压缩阶数N=2p′+1时,无论p′=2m(m=0,1,2,…,…)还是p′=2m+1(m=0,1,2,3,…,…),只要各模的初始相位φj满足一定的量子条件,则当两态叠加几率幅满足rpq(I)=rnq(R)时,态|Ψ(2)〉q就恒处于N-Y测不准态,始终不呈现N-Y最小测不准态和N次方Y压缩;而当rpq(I)≠rnq(R)时,态|Ψ(2)〉q始终不呈现N-Y测不准态、N-Y最小测不准态和N次方Y压缩效应。 相似文献
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A method of multi-pulse discriminating frequency and high probability average value filtering is presented for offset frequency locking with ns laser pulses. In the experiment, the frequency locking for cavity-dumped CO2 laser with 100 ns pulse width and the repetition rate of 10 kHz was studied. The precision was up to ±2 MHz at the heterodyne frequency 90 MHz. However, it is more than ±10 MHz for the single pulse discriminating frequency. This method can also be applied to laser offset frequency locking for many kinds of short pulse lasers. 相似文献
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Efficient continuous-wave (cw), passively Q-switched, and actively Q-switched laser operations are demonstrated with a mixed vanadate crystal of Nd:Gd0.18Y0.82VO4 under diode pumping. In a cw operation, an output power of 8.25 W is obtained at a maximum available incident pump power (Pin) of 15 W, with a slope efficiency of 56%. Using a Cr4+:YAG crystal of initial transmission of 62% as the saturable absorber for Q-switching, an average output power of 3.05 W is generated at pulse repetition frequency (PRF) of 16.7 kHz when the laser is pumped with the same maximum Pin. The pulse energy, pulse duration, and peak power are 183.3 μJ, 6.0 ns, and 30.6 kW, respectively. When actively Q-switched by an acousto-optic modulator, the laser produces an average output power of 5.5 W at PRF of 30 kHz with 16.2 W of pump power incident upon the laser crystal. The pulse energy, duration, and peak power are measured to be 183 μJ, 10.5 ns, and 17.5 kW, respectively. 相似文献
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A tunable electrooptically Q-switched RF excited waveguide CO2 laser with two channels is presented. Q-switched pulses have been obtained from one of the channels. The peak power is 300 W and the pulse width is 140 ns. CW laser output has been obtained from the other channel, which can been tuned by a PZT. The short-term heterodyne stability can be up to 10−9. 相似文献
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A passively Q-switched a-cut Nd:YVO4 self-stimulating Raman laser using a Cr:YAG saturable absorber has been demonstrated for the first time. The maximum average
output power of the self-Raman laser at 1176 nm is 347 mW at the incident pump power of 10 W with a pulse repetition frequency
(PRF) of 66 kHz. The pulse width, pulse energy of the 1176 nm are found to be 10 ns and 5.6 μJ. The conversion efficiency
from diode laser input power to Raman output power is 3.47%. 相似文献
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C. Q. Gao Y. S. Zhang M. W. Gao Y. Zheng L. Wang R. Wang Z. Y. Wang 《Laser Physics》2011,21(11):1884-1887
A laser diode (LD) side-pumped 2 μm single-frequency Q-switched Tm:YAG laser was demonstrated. The laser was injection seeded
by a CW single frequency Tm:YAG laser with a twisted-mode cavity. The maximum single-frequency pulse energy was 16.3 mJ, with
a pulse width of 570 ns and a pulse repetition rate of 10 Hz. The linewidth of the 2 μm single-frequency Q-switched laser
was 0.68 MHz, measured by using the optical heterodyne technique. The M
2 of the laser beam was measured to be 1.09 and 1.03 for x direction and y direction, respectively. 相似文献
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为了提高反鱼雷鱼雷(ATT)激光近炸引信对来袭鱼雷的捕获率,首先根据鱼雷目标的激光反射特性,分析了鱼雷目标回波功率随激光束入射角度和入射位置的变化规律。采用空间解析几何方法描述了ATT与来袭鱼雷的交会模型,给出了任意交会距离和姿态时目标回波功率计算方法。根据系统最小探测功率,建立了水中单光束扫描激光引信捕获率蒙特卡罗仿真模型,仿真了系统捕获率随激光脉冲频率的变化关系,获得了探测不同距离目标的最大捕获率和相应的激光扫描频率和脉冲频率。结果表明:当激光扫描频率为15Hz,脉冲频率为4kHz,系统能可靠捕获距离9m内目标。所得系统捕获率仿真模型和结果可为ATT单光束扫描激光引信系统设计提供理论参考。 相似文献
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本文主要简介我国变象管、双近贴象增强器毫微秒分幅相机的研制现状,并讨论这些相机的快门脉冲发生器电路。同时还介绍了用于带微通道板光电倍增管的选通电路。这些电路作适当修改后可用于微光硅靶摄象管的控制,高压电器特性试验,毫微秒脉冲源以及激光调制等场合中。 相似文献
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Shu-Di Pan Ke-Zhen Han Xiu-Wei Fan Jie Liu Jing-Liang He 《Optics & Laser Technology》2007,39(5):1030-1032
A coherent UV passively Q-switched diode pumped Nd:GdVO4 laser source is proposed. During pumping of the β-BBO crystal a stable light with power 0.6 W with wavelength 532 nm and pulse duration 9 ns at frequency repetition 16 kHz was applied. The output UV light has a power about 79 mW at wavelength 266 nm during diode-pumping with 8 W incident light. 相似文献