Phase-locked laser coherent interference

A method of locking the relative phase to provide stable constructive or destructive interference between the phase-modulated sidebands from a pair of phase modulators is demonstrated. It is discussed theoretically for optimal fringe visibility related to the phase noise from faulty system. After phase locking using the phase modulating and lock-in technique,the drift of the relative phase is focalized around ±0.0016 rad and the fringe visibility is restricted to 2×10-4 .     

谐波探测在Cs原子饱和吸收光谱中的应用

使用低频波长调制和高次谐波探测来测量Cs原子D₂线6S_1/2(F=4)→6P_3/2(F’=3、4、5)跃迁的方法,对谐波信号的展宽特性和灵敏度进行了分析.结果显示,减小调制电压可以压窄线宽,提高分辨率;在一定范围内增大调制电压可以提高谐波信号强度,提高测量灵敏度;提高分辨率要以损失灵敏度为代价.提高谐波次数可以提高分辨率.高次谐波可以获得高的灵敏度和分辨率.     

四能级原子量子相干过程中瞬态光学特性

利用半经典理论研究了N-型四能级相干原子的瞬态光学特性。理论分析表明：当信号光开启的瞬间，介质对探针光的非线性吸收从接近于零的状态迅速增加，经过驰豫振荡过程，趋于稳定状态。本文的研究结果将为吸收型光子开关的设计提供理论依据和参考。     

连续变量纠缠交换对系统物理参量的依赖关系

以量子关联度和相干态量子离物传送的保真度为判据，在增益因子取1和取最佳值两种情况下，计算了纠缠交换的质量对探测效率，传输效率及初始关联参量的函数依赖关系。计算结果可给实验设计提供有用参考。     

LD端面抽运的全固化单频蓝光激光器

用激光二极管(LD)抽运Nd YAG晶体,采用四镜环行腔,腔内放置TGG晶体和λ/2波片,组成光学单向器,利用LBO晶体内腔倍频技术,实现单频946 nm红外光和473 nm蓝光输出.最大单频蓝光输出12 mW,红外光输出13 mW,光束x方向的M2为1.02,Y方向的M2为1.14.腰斑的不对称性为1.062.自由运转情况下,功率波动小于±1.5%,频率稳定性优于±5.4 MHz.     

螯合剂对稀土-转铁蛋白配合物的影响Ⅲ——柠檬酸脱除Tb_c-Tf中铽(Ⅲ)的动力学研究

通过监测人血清脱铁转铁蛋白C-端结合部位结合铽(Ⅲ)(Tb_C-Tf)在549nm处荧光强度随时间的变化,在0.1mol·L~(-1)Hepes,pH7.4及室温条件下观察了柠檬酸对人血清脱铁转铁蛋白结合铽(Ⅲ)的脱除。结果表明,柠檬酸对人血清脱铁转铁蛋白结合铽(Ⅲ)的脱除有两种途径:饱和动力学和一级反应动力学途径。     

铯原子调制转移光谱在激光稳频中的应用

利用铯原子D₂线的调制转移光谱的鉴频特性,实现了光栅外腔式主振荡器-功率放大型(MOPA)半导体激光器相对于铯原子6²S_1/2F=4→6²P_3/2 F’=5超精细跃迁的偏频锁定,在100 ms内激光频率的相对起伏小于±280 kHz.相对于一般的饱和吸收锁频方法而言,调制转移光谱在锁频中的应用不仅彻底消除了Doppler背景对锁频的影响,而且还避免了对激光器直接进行频率扰动而带来的附加频率噪音.     

靶材料BRDF现场模拟测量

介绍一种利用频率调制光谱技术,在自然环境光下进行材料双向反射分布函数(BRDF)的测量方法.用该方法对若干墙面靶材料的反向散射双向反射分布函数进行了测量,并给出了被测材料的BRDF拟合函数参量.测量环境模拟了以墙面材料为反射靶的激光现场遥感探测气体测量环境,其结果对此类探测仪器的设计具有指导意义.     

A CATASTROPHE ANALYSIS ON THE STABILITY OF THE CRACK GROWTH IN THREE-POINT BENDING SPECIMENS

This paper presents an attempt at the application of catastrophe theory to the stabilityanalysis of J-controlled crack growth in three-point bending specimens. By introducing the solutions ofJ-integral in the completely yielding state for the ideal plastic material, the critical condition of losingstability for the crack propagation in the specimen is obtained, based on the cusp catastrophe theory.The process of the crack growth from geometrical sense is described.     

Methane sensor based on palladium/MWNT nanocomposites

Methane gas sensor was fabricated based on electrocatalytic properties of the Pd/MWNT nanocomposites on indium tin oxide (ITO)glass substrates.A linear response for methane was obtained in the range of 0-16%(v/v)with a detection limit of 0.167%(v/ v)and R.S.D.of 4.1%.After 100 times sensing or stable stored more than 12 months in atmosphere,unconspicuous measurable decrease was observed.The response time was less than 60s at room temperature and ambient pressure.Some common potential interferents in samp...