Optimization of Output Properties for Bias Signal-Modulated in a Single-Mode Laser

Defining the quantity K as the signal-to-noise ratio （SNR） and the normalized intensity fluctuation C（O） of a single-mode laser for bias signal modulation driven by color noises with colored correlation, the whole output properties of the laser system is described by K. It is found that there is a maximum in the curves of K versus D, Q, and io. The optimization parameters are gained.     

三元共聚硅烷的结构与性能

三元共聚硅烷的结构与性能;Wurtz偶合反应;热稳定性;光学性质     

Effects of periodic modulation on the nonlinear Landau--Zener tunneling

We study the Landau-Zener tunneling of a nonlinear two-level system by applying a periodic modulation on its energy bias. We find that the two levels are splitting at the zero points of the zero order Bessel function for high-frequency modulation. Moreover, we obtain the effective coupling constant between two levels at the zero points of the zero order Bessel function by calculating the final tunneling probability at these points. It seems that the effective coupling constant can be regarded as the approximation of the higher order Bessel function at these points. For the low-frequency modulation, we find that the final tunneling probability is a function of the interaction strength. For the weak inter-level coupling case, we find that the final tunneling probability is more disordered as the interaction strength becomes larger.     

Yb(Cl_4)_3·3H_2O-18C6-C_2H_5OH体系(25℃)的相化学研究及固态配合物的合成与性质

王冠醚能选择性配位于阳离子,使无机盐溶于有机溶剂及类似酶功能的特性,因而引起人们很大的研究兴趣。文献［１］报道在乙腈中制得了组成为：Ｃｅ（ＣＩＯ４）３·１８Ｃ６的配合物;文献［２］在乙腈中制得了组成为 ＲＥ（ＣＩＯ４） ３· １８Ｃ６（ＲＥ＝ Ｐｒ, Ｅｕｆ）的配合物;而 ＲＥ（ＣＩＯ４） ３·３Ｈ２Ｏ－１８Ｃ６－ＣＨ３ＣＮ体系（ＲＥ＝ Ｄｙ, Ｙ）的相化学研究指出：体系中均形成两种化学计量的配合物［３·４］。Ｙｂ（ＣＩＯ４）３·３Ｈ２Ｏ与１８Ｃ６在乙醇中的配合行为未见报道。为了寻找制备配合物的热力学依…     

Experimental and theoretical studies of a high repetition rate fiber laser, mode-locked by external optical modulation

An experimental and theoretical study of a high repetition rate laser source operating on a novel mode-locking technique is presented. This technique relies on the fast saturation and recovery of a semiconductor optical amplifier induced by an external optical pulse and has been used to obtain 4.3 ps pulses at 20 GHz. A complete mathematical model of the fiber ring laser is presented describing the mode-locking process in the laser oscillator and providing solutions for the steady-state mode-locked pulse profile. The critical parameters of the system are defined and analyzed and their impact on the formation of the mode-locked pulses is examined. The comparison between the theoretical results and the experimental data reveals very good agreement and has allowed the optimization of the performance of the system in terms of its critical parameters.     

微型Nd：YVO4激光器在碘分子调制转移光谱中的应用

以半导体激光器抽运微型Nd:YVO4倍频激光器为光源获得碘分子在532nm处的光外差调制转移光谱信号,并对获取最佳稳频信号的实验条件进行了讨论。     

射频激励双通道不等长电极波导CO2激光器的外差频率调制研究

报道了采用不等长电极结构的射频激励双通道波导CO₂激光器,通过调节射频电源功率的方法可以调谐双通道输出激光的外差频率,其调谐率约为0.1 MHz/W。在未采取任何稳频措施时,其短期外差频率稳定性可达10-10。还在理论上分析了射频功率调谐外差频率的原理。     

双闭环光纤陀螺控制回路研究

本文讨论了采用数学据齿波和方波调制方案的闭光纤陀螺系统的实现。在此基础上,进一步研究了针对消除由于斜坡复位幅度２π不精确给系统带来的误差而设计的第二闭环回路（幅值回路）。结果表明：第二闭环回路的加入能很好地在短时间内消除由复位幅度２π不精确带给系统的偏差。     

基于软件编码的FLEX高速寻呼测试仪的研制

基于FLEX和POCSAG寻呼协议,采用单片机AT89C55为控制核心,以MCS-5l汇编语言实现软件编码,研制了一套兼容POCSAG协议的FLEx高速寻呼测试仪．本文详细讨论了实现FLEx高速寻呼协议的软件编码技术．在对数据块进行交织时,提出了一种简化的软件编码措施,将多相复用模式的交织数据块简化为单相模式进行处理,从而减小了编码难度．     

TDLAS波长调制压力测量法参数优化

使用TDLAS技术进行动态压力测量已经成为压力测量领域的研究热点。波长调制法实验装置较为复杂,需要对多个参数进行设置,选择出最优的预设参数能够取得更好的实验效果,获得更高的测量精度。目前波长调制法的实验参数设置基本凭借个人经验,使用Matlab程序仿真结合波长调制法的TDLAS测量技术,能够对实验中需要进行预设的重要参数进行了分析。通过计算4990cm-1波段和6330cm-1波段附近的多条吸收峰,发现4990.09cm-1波段处的吸收峰更适合作为波长调制法的测量波段。以4990.09cm-1处的吸收峰为研究对象,进行了波长调制法压力测量仿真建模,计算了调制度、调谐频率和调制频率对二次谐波幅值和对称性的影响并深入地分析了影响因素,总结了其变化规律。在综合考虑抗噪性能和测量精度的情况下,选择了调制度为2.5,调谐频率30Hz,调制频率5kHz为最佳实验参数。基于Matlab的仿真模型能够快速计算大量参数点,更加直观地分析出对参数的影响趋势,为实验仪器和预设参数的选择提供依据。