低功耗便携式心电记录仪的设计

主要阐述了低功耗便携式心电记录仪的设计方法，郑重介绍了便携式心电记录仪中单片机和存储器的低功耗运行以及低功耗应用系统在软件设计时应采取的措施。     

Beat signal compression by loop mirror constructed with linear dispersion decreasing fiber

A nonlinear optical loop mirror (NOLM) constructed with linear dispersion decreasing fiber (DDF) is used to compress a beat signal. Several factors impacting on quality of output pulse in this compression system, such as dispersion slope of DDF, power-splitting ratio, incident pulse shape and peak power, are analyzed numerically. The new method for selecting device characteristics is adopted to enable both good pedestal suppression and pulse compression. As a result, the output pulse train with tunable and high repetition rate, pedestal energy of 5.09%, compression ratio of 25.6 and energy transmissivity of 50.56% is obtained by using 0.524 km-long DDF with dispersion slope of 26 ps²/km² and a coupler with power-splitting ratio of 0.54.     

激光穴位照射转胎40例

He-Ne激光照射至阴,少冲穴40例与胸膝卧位35例对照。纠正胎位治疗肯定,方法简便,疗程短,无副作用,安全无痛苦,降低臀位产,减少剖腹产和新生儿死亡率等优点。激光穴位照射具有针灸作用,使穴位兴奋,代谢加强,引起机体功能变化,从而达到矫正胎位的目的。     

关于Smarandache函数的一个问题

对任意正整数n,著名的Smarandache函数S(n)定义为最小的正整数m使得n|m!.即就是S(n)=min{m:m∈N,n|m!}.令PS(n)表示区间[1,n]中S(n)为素数的正整数n的个数.在一篇未发表的文献中,J. Castillo建议我们研究当n→∞时,比值PS(n)/n的极限存在问题.如果存在,确定其极限.本文的主要目的是利用初等方法研究这一问题,并得到彻底解决!即就是证明该极限存在且为1.     

基于LiNbO_3的长周期波导光栅可调谐耦合器的设计

设计了一种基于LiNbO_3的长周期波导光栅可调谐耦合器.该耦合器利用长周期光栅的独有特性将输入波导的导模经包层模耦合至输出波导导模.由于LiNbO_3的电光效应,波导光栅芯层与包层的有效折射率随外加电压变化,从而耦合器的谐振波长及耦合效率可由外加电压调谐.分析了光栅周期与耦合器的长度对耦合器带宽和耦合效率调谐范围的影响,以及波导尺寸对谐振波长调谐灵敏度的影响.结果表明光栅周期越短,耦合器长度越长,则耦合器的带宽越窄,耦合效率调谐范围也越大.此外,谐振波长调谐灵敏度随波导宽度的增加而减小,而波导厚度对谐振波长调谐灵敏度的影响可以忽略.对光栅周期为94μm、长度为3.52cm的耦合器进行仿真,结果表明,谐振波长灵敏度为26.2pm/V,3dB带宽可达4.5nm,当外加电压从0变化到200V时,谐振波长变化5.24nm,耦合效率可在1到0.15之间进行调谐.     

共晶炉控制系统的开发及工艺研究

共晶技术是近几年发展起来的新型微组装工艺,较传统的粘接工艺有许多优点,应用日趋广泛.共晶炉是用于共晶粘接的专用设备.结合设备的结构和控制原理,对共晶炉控制硬件和软件系统的设计开发进行了详细阐述;同时,结合设备对共晶工艺和工艺参数进行了论述.     

光子晶体光纤应用于光时钟恢复的实验研究

实验研究了以注入锁定光参量振荡器(OPO)为工作机制的10Gb/s的光时钟恢复系统。携带信息的高速信号光作为OPO的注入锁定触发源,OPO的输出作为恢复的光时钟,OPO中的非线性光子晶体光纤(PCF)不仅提供动态的非线性增益,同时也提供了OPO模式锁定机制。实验得到恢复时钟的脉冲宽度大约为3.6ps,时间带宽积约为0.45,时间抖动约为252fs。     

基于级联多模布拉格光栅和高精细度滤波器的可调谐双波长窄线宽掺铒光纤激光器

提出了一个基于级联多模布拉格光栅和新型的高精细度滤波器的可调谐双波长窄线宽掺铒光纤激光器的结构。环形滤波器由两个耦合器和一段经过泵浦的掺铒光纤组成,由于掺铒光纤产生增益,滤波器产生高精细度的频率响应,能够滤掉掺铒光纤激光器的不需要的纵模,从而起到窄化激光器线宽的作用。实验过程中,由多模光栅的选频特性产生六种窄线宽双波长的组合,激光器的线宽由不加滤波器的0.14~0.16 nm 被压窄窄化到0.05 nm。     

Humidity and temperature sensor based on GOQDs-PVA coated tapered no-core fiber combined with FBG

A simple structure optical fiber sensor for relative humidity (RH) and temperature measurement is proposed and verified in this paper, which is based on graphene oxide quantum dots and polyvinyl alcohol (GOQDs-PVA) composite coated tapered no-core fiber (NCF) combined with a fiber Bragg grating (FBG). FBG is insensitive to humidity and sensitive to temperature, which is used to compensate temperature of the sensor. Experimental results show this sensor has humidity sensitivity of 143.27 pm/%RH ranging from 30%RH to 80%RH and the temperature sensitivity of 9.21 pm/℃. The proposed sensor has advantages of simple structure, good repeatability, and good stability, which is expected to be used in both RH and temperature measurement in biological and chemical fields.     

A dynamic optical arbitrary waveform generator based on cross phase modulation

In this paper, a dynamic optical arbitrary waveform generator (OAWG) based on cross phase modulation (XPM) is proposed. According to the characteristics of XPM, the nonlinear phase shift of signal can be changed along with the pump power. The amplitude of signal can be changed by controlling the phase shift at one arm of a Mach-Zehnder interferometer (MZI) using XPM effect between signal and pump. Therefore, the phase and amplitude of the optical frequency comb (OFC) can be controlled by two pump arrays. As a result, different kinds of waveforms can be synthesized. Due to the ultrafast response of XPM, the generated waveform could be dynamically updated with an ultrafast frequency. The waveform fidelity is affected by the updating frequency.