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高次模下矩形巷道形状因子对电磁波的影响 被引量:1
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作者 王旭启 《工矿自动化》 北大核心 2019年第5期68-72,共5页
不同形状的巷道内电磁波的传播特性不同,在不同次模情况下的电磁波传播特性也不相同。在分析电磁波传输理论和多波模理论的基础上,利用计算机对高次模情况下矩形巷道形状因子对电磁波传播衰减的影响进行了仿真研究。仿真结果表明,在矩... 不同形状的巷道内电磁波的传播特性不同,在不同次模情况下的电磁波传播特性也不相同。在分析电磁波传输理论和多波模理论的基础上,利用计算机对高次模情况下矩形巷道形状因子对电磁波传播衰减的影响进行了仿真研究。仿真结果表明,在矩形巷道形状因子一定时,随着电磁波传输模式的升高,电磁波的衰减越来越大;不同模式时,随着形状因子的增大,电磁波衰减曲线的斜率不变;水平极化模式时,随着形状因子的增大,电磁波的衰减先减小后增大,在形状因子为1.7时,衰减率最小;垂直极化模式时,随着形状因子的增大,衰减曲线也呈现先减小后增大的趋势,在形状因子为0.7时,衰减率最小;在形状因子等于1时,水平极化模式与垂直极化模式对电磁波传播衰减的影响相同,形状因子小于1时,垂直极化模式对电磁波衰减的影响大于水平极化模式,形状因子大于1时,水平极化模式对电磁波传播衰减的影响大于垂直极化模式。 展开更多
关键词 煤矿井下通信 矩形巷道 形状因子 高次模 电磁波衰减 水平极化模式 垂直极化模式
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Vertical cavity surface emitting laser transverse mode and polarization control by elliptical hole photonic crystal
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作者 曹田 徐晨 +4 位作者 解意洋 阚强 魏思民 毛明明 陈弘达 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第2期261-264,共4页
The polarization of traditional photonic crystal(PC) vertical cavity surface emitting laser(VCSEL) is uncontrollable,resulting in the bit error increasing easily.Elliptical hole photonic crystal can control the tr... The polarization of traditional photonic crystal(PC) vertical cavity surface emitting laser(VCSEL) is uncontrollable,resulting in the bit error increasing easily.Elliptical hole photonic crystal can control the transverse mode and polarization of VCSEL efficiently.We analyze the far field divergence angle,and birefringence of elliptical hole PC VCSEL.When the ratio of minor axis to major axis b/a = 0.7,the PC VCSEL can obtain single mode and polarization.According to the simulation results,we fabricate the device successfully.The output power is 1.7 mW,the far field divergence angle is less than 10°,and the side mode suppression ratio is over 30 dB.The output power in the Y direction is 20 times that in the X direction. 展开更多
关键词 photonic crystal vertical cavity surface emitting laser(VCSEL) elliptical holes single mode polarization control
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各向异性光反馈注入的垂直表面发射激光器的矢量偏振模转换机理 被引量:5
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作者 钟东洲 曹文华 +1 位作者 吴正茂 夏光琼 《物理学报》 SCIE EI CAS CSCD 北大核心 2008年第3期1548-1556,共9页
数值研究了各向异性光反馈注入的垂直表面发射激光器(VCSEL)的矢量偏振模转换机理,研究结果表明,首先,当注入电流接近阈值电流时,由VCSEL的外部参数和偏振器控制的光反馈注入量中各偏振模的能量决定VCSEL输出的偏振态.其次,由偏振器控... 数值研究了各向异性光反馈注入的垂直表面发射激光器(VCSEL)的矢量偏振模转换机理,研究结果表明,首先,当注入电流接近阈值电流时,由VCSEL的外部参数和偏振器控制的光反馈注入量中各偏振模的能量决定VCSEL输出的偏振态.其次,由偏振器控制的各向异性光反馈注入引起的VCSEL输出偏振态呈周期性变化.另外,当由偏振器控制的反馈注入量中的^x偏振和^y偏振模能量相当时,^x偏振模和y^偏振模之间竞争激烈,而激光器外部微小的扰动都会打破这两种偏振模竞争平衡,从而使激光器输出偏振态对外部参数变化非常敏感.最后,当注入电流远大于阈值电流时,^y偏振模增益获得足够大,这时VCSEL输出为稳定的y^偏振,即VCSEL的输出偏振态与其他参数无关. 展开更多
关键词 各向异性光反馈 垂直表面发射激光器 矢量偏振 转换机理
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Mode hopping and polarization switching of mutually coupled vertical-cavity surface-emitting lasers
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作者 ZHANG WeiLi PAN Wei LUO Bin WANG MengYao ZOU XiHua 《Science in China(Series F)》 2008年第5期592-598,共7页
We perform a theoretical study on the polarization-resolved compound lasing mode (CLM) of two mutually coupled vertical-cavity surface-emitting lasers (VCSELs). Different solutions of CLMs are derived though stabi... We perform a theoretical study on the polarization-resolved compound lasing mode (CLM) of two mutually coupled vertical-cavity surface-emitting lasers (VCSELs). Different solutions of CLMs are derived though stability analysis of the spin-flip model. The dynamical evolvements of CLMs with the existence of polarization degrees of freedom are also charactered. The most stable CLM with the smallest carrier density tend to be excited, since the gain needed for this mode to emit is the lowest. In the given system, varying values of injection rate or birefringence, etc., will change the generation of the preferred CLMs in the two polarization directions, and thus influence the polarization switching (PS) characteristics. Thus, hoppings between CLMs are also companied by PSs. Through mapping of average power in the parameter space, the influences of coupling rate and anisotropy parameters (linear dichroism and linear birefringence) on PS and hopping between CLMs are discussed. 展开更多
关键词 vertical-cavity surface-emitting semiconductor laser polarization switching mutual injection mode hopping
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