排序方式: 共有10条查询结果,搜索用时 46 毫秒
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为了提高系统数据流通率,结合空时预编码技术,提出一种基于多天线相关信道反馈的低复杂度自适应格形编码调制(TCM)系统.利用二维波束成型的变换作用,使得在大天线数情况下,也具有满空时编码速率.给出系统误比特率性能分析表达式,并在此基础上得到最优空时码预编码方式.在满足系统预设可靠性要求下,获得自适应格形编码正交幅度调制(QAM)设计准则.实验结果显示能获得高数据流通率. 相似文献
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通过计算给出了在LHC能区非对心核 核碰撞中由椭圆流ν2 表示的高横动量直接光子的方位角不对称性。该高横动量光子是由喷注与热密介质相互作用而辐射出来的。光子椭圆流与强子椭圆流ν2 相差π/2的相位, 是直接光子椭圆流中负值的来源。同时, 计算表明LHC能区直接光子ν2随粒子横动量pT的变化趋势与RHIC上的实验结果一致, 但LHC能区较RHIC能区有更低的直接光子流ν2 值, 且ν2 值由负到正对应的转换pT值更高。这表明在LHC能区喷注淬火效应更为明显, 表面发射的直接光子对光子椭圆流的贡献份额增强。The azimuthal anisotropy of high pT direct photons is investigated by using the coefficient of elliptic flow ν2 in non-central nucleus-nucleus collision at LHC energies. These photons come from radiation induced by the interaction between jet and hot/dense medium. The azimuthal anisotropy of high pT direct photons is investigated by using the coefficient of elliptic flow ν2 in non-central nucleus-nucleus collision at LHC energies. These photons come There is π/2 difference between direct photons and hadrons for the azimuthal elliptic flow ν2. Such photons are the main source of the negative part of ν2 for direct photons. The dependence of the direct photon ν2 on the transverse momentum pT at LHC energy is found to be consistent with the experimental results at RHIC energy. Furthermore, we find that the value of the direct photon ν2 at LHC energy is smaller than that at RHIC energy. The value of the transverse momentum at which the direct photon ν2 changes from negative value to positive at LHC is higher than that at RHIC. It’sfound the enhanced jet quenching effect and enhanced contribution for the elliptic flow ν2 of the direct photons emitted from surface at LHC energy. 相似文献
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1.55 μm偏振无关半导体光放大器腔面减反膜的研制 总被引:3,自引:3,他引:0
设计并制作了1.55 μm偏振无关半导体光放大器腔面TiO2/SiO2多层减反膜, 工艺过程中设计并使用了反射率实时监控装置, 得到了低于5×10-4的腔面剩余反射率. 器件测试结果表明, 管芯在250 mA电流下仍处于未激射状态, 表明减反膜有效抑制了芯片的激射. 半导体光放大器的自发辐射(ASE)谱波动在0.4 dB以下, 3 dB带宽大于52 nm, 半导体光放大器小信号增益近27 dB, 在1520~1580 nm波长范围内偏振灵敏度小于0.5 dB. 相似文献
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采用低压金属有机气相外延 (LP MOCVD)设备生长并制作了 1 5 5 μmAlGaInAs InP偏振无关半导体光放大器 ,有源区为 3周期的张应变量子阱结构 ,应变量为 0 35 % ;器件制作成脊型波导结构 ,并采用 7°斜腔结构以有效抑制腔面反射 ;经蒸镀减反膜后 ,半导体光放大器的自发辐射功率的波动小于 0 3dB ,3dB带宽为 5 0nm ,半导体光放大器小信号增益近 2 0dB ,带宽亦为 5 0nm .在 1 5 30— 1 5 80nm波长范围内偏振灵敏度小于 0 5dB ,峰值增益波长的饱和输出功率达 7dBm ;器件增益随温度的升高而减小 ,当器件工作温度从 2 5℃升高至 6 5℃时 ,增益降低小于 3dB . 相似文献
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All-optical XNOR and AND gates simultaneously realized in a single semiconductor optical amplifier with improved dynamics 下载免费PDF全文
All-optical XNOR and AND logic gates using four-wave mixing (FWM) and
cross-gain modulation (XGM) in a single semiconductor optical
amplifier (SOA) with improved dynamics are simultaneously realized.
By numerical simulation, the effects of the input optical wave powers
and injection current on the critical factors of the logic gate
performances, such as the ON--OFF contrast ratio, the power-output
level of the logic `1', and the difference between power outputs of
the logic `1', are investigated in detail. In addition, the effect of
the counter-propagating CW pump on the gain recovery is analysed. 相似文献
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提出了一种新型的基于多电极单端耦合半导体光放大器(SOA)的交叉增益调制(XGM)型波长转换方案,并建立了这种波长转换器完整的宽带理论模型.通过数值模拟的方法,比较了基于多电极单端耦合SOA的XGM型波长转换和基于单电极单端SOA的XGM型波长转换的输出特性,结果表明前者的输出消光比优于后者,而且啁啾特性也略有改善.
关键词:
多电极
波长转换
单端耦合半导体光放大器
交叉增益调制
消光比
啁啾 相似文献
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采用低压金属有机化学气相外延设备进行了1.3μm压应变量子阱材料、张应变量子阱材料和混合应变量子阱材料的生长研究.通过x射线双晶衍射和光致发光谱对生长材料进行测试和分析.基于四个压应变量子阱和三个张应变量子阱交替生长的混合应变量子阱(4CW3TW)结构有源区,并采用7°斜腔脊型波导结构以有效抑制腔面反射,经蒸镀减反膜后,半导体光放大器光纤光纤小信号增益达21.5dB,在1280—1340nm波长范围内偏振灵敏度小于0.6dB.
关键词:
偏振无关
应变量子阱
半导体光放大器
减反膜 相似文献
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