Symmetry between the transfer properties of micro-ring resonators with gain and with loss

Gain and loss affect the performance of dispersive micro-ring resonator systems significantly. Through analysing the transfer functions of two-port ring-resonator (TPRR) circuits and coupled micro-ring resonators, the symmetry between the transfer properties of micro-ring resonators with loss and with gain is discovered. For two TPRRs whose attenuation and gain coefficients are equal to each other, or for two coupled micro-ring resonators whose counterparts have equal gain and loss respectively, their intensity transmissions are reciprocal, while the phase shifts and dispersions are the same. This symmetry demonstrates the action mechanism of loss and gain on the transmissions and dispersions of these micro-ring resonators. It is useful for analysing and designing micro-ring resonators in group velocity control and dispersion compensation applications.     

Theoretical investigation of phase-based all-optical logic gates based on AlGaAs microring resonators

We propose and numerically verify a phase-based all-optical logic gates (AND, OR, XOR, NOT, NAND, NOR and XNOR, i.e. all seven basic logic gates) operation scheme based on cascaded AlGaAs microring resonators. The logic function realization is supported by the signal light phase change and extraction, the phase control in this scheme depending on cross phase modulation (XPM) in the AlGaAs microring. By inputting a non-return zero (NRZ) intensity signal as pump light, the probe light (continuous-wave, CW) will experience different phase shift and then a phase-based logical function can be obtained in this process. By choosing different pump power level, reference phase and the output port of a Mach–Zehnder interferometer (MZI), all seven basic logic operations can be realized by using the same device. The modulation depth, bandwidth and minimum power requirement of this scheme have also been discussed in detail.     

自聚焦棒外腔半导体激光器稳态特性的研究

本文研究了自聚焦棒外腔半导体激光器的多模速率方程,在此基础上对自由运转半导体激光器和自聚焦棒外腔半导体激光器稳态特性进行了对比数值分析。分析表明:自聚焦棒外腔光反馈大大提高了激光器的边模抑制比,可以实现半导体激光器的高边模抑制比单纵模运转;同时降低了激光器的阈值电流,提高了输出功率。对数值分析结果进行了实验验证。在国内首次实现自聚焦捧外腔半导体激光器的单纵模运转,其边模抑制比大于35 dB,光谱线宽小于21 MHz,谐振波长调谐范围达110(?)。     

高性能声表面波调频振荡器的研究

分析了声表面波谐振器的性能 ,论述了声表面波振荡器的工作原理及设计方法 ,最终完成中心频率为797.3 MHz的振荡电路 ,调频带宽 2 MHz(2 5 0 0 PPM)。文中对影响调频带宽、相位噪声的因素进行了分析讨论。本项目研究成果已获得实际应用     

A piezoelectric transducer‐tuned microstrip‐ring resonator oscillator operating at the second resonant mode of the ring resonator

A microstrip open‐loop resonator oscillator operating at even modes is proposed. The even mode of the ring circuit can be predicted by using a simple transmission‐line model. The new oscillator has a characteristic similar to that of a push‐push oscillator. In addition, in comparison with the push‐push oscillator, the new oscillator with one active device can minimize the size and lower the cost. A voltage‐controlled piezoelectric transducer (PET) is used to vary the resonant frequencies of the ring resonator, which in turn tunes the oscillator with a good tuning range of 4.9% at around 12.1 GHz. This tuned oscillator should have many applications in wireless systems. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005.     

种子注入式单纵单横电光调Q激光器

基于种子注入技术、干涉法腔模锁定方案以及自滤波非稳腔技术,设计并研制出一套单纵单横电光调Q脉冲激光器系统。该系统输出的基波(波长1064nm)能量达到600mJ,倍频后绿光能量达到300mJ,发散角接近衍射极限,线宽接近傅里叶变换极限,在强气流强振动环境中单纵模的锁定概率为100%。实验观测了种子注入对巨脉冲建立时间、光斑模式以及能量的影响。该系统可应用于受激布里渊散射(SBS)、大视场风洞全息以及光学合成孔径等研究领域。     

一种体声波滤波器仿真设计分析

文中着重阐述了基于微机电系统（Micro-Electro-Mechanical Systems，MEMS）技术制造的薄膜体声波谐振器／滤波器，简述了它的结构及原理，分析了其主要特征参数和设计方法，并设计了中心频率为2．4GHz，带宽为100MHz的带通滤波器，展示了薄膜体声波谐振器／滤波器的突出性能，为通信MEMS技术的微型化发展提供了更广阔的道路。     

声表面波谐振型无源无线温度传感器硬件系统

介绍了一种基于声表面波谐振器的无源无线温度传感系统,系统采用一次变频的构成方式,解决了传统传感系统存在电路结构复杂和控制灵活性差的缺点,给出了系统的具体构成、工作原理和天线的设计。与传统系统构成相比,本系统的构成更简洁,操作性和灵活性更强。实验验证了本系统构成方式的可行性和天线设计的优点。     

谐振式光纤陀螺调相谱检测技术中的光克尔效应

谐振式光纤陀螺(R-FOG)是基于Sagnac效应产生的谐振频率差来测量旋转角速率的一种新型光学传感器。信号检测技术和系统中存在的各种噪声对系统的检测精度有着重要的影响。基于调相谱检测技术的谐振式光纤陀螺系统中,除顺时针(CW)和逆时针(CCW)光路传播的光强不均匀会引入非互易相位差,使系统出现零漂外,顺时针和逆时针光路的调制系数也会引入系统零漂。光克尔效应引入的系统零漂与系统的真实旋转在测量时是无法区分的,因此成为主要的噪声之一。通过光波场叠加原理,推导得到调相谱检测方案下的谐振式光纤陀螺系统中,光克尔效应引起的系统零漂的解析表达式。依据光克尔效应产生的零漂不随陀螺转速的改变而变化,利用简单的开环系统,对光克尔效应引入的陀螺零漂进行了测试。     

串联谐振法测量1/4波长介质同轴谐振器的特性参数

本文介绍一种测量1/4波长介质同轴谐振器主要特性参数的方法.介质同轴谐振器等效为并联谐振回路,直接串入线路无法测量其参数,本文提出串联谐振法,即在谐振器的开路端串联一只高Q值的电容器,形成串联谐振回路,用网络分析仪测量其传输曲线,从曲线上直接读出该回路的谐振频率和Q值,然后用本文推导出的公式便可计算得出谐振器的谐振频率和无载Q值.本文还用介电常数为74的陶瓷材料制成了1/4波长介质同轴谐振器进行了一系列的实验,实验结果表明,该方法简单,非常实用.