超短脉冲激光及其应用

评述了国际上超短脉冲激光技术的最新研究进展以及超短脉冲激光在超高速光通讯、海量信息存储、光合作用研究、化学反应过程研究等领域广泛的应用状况     

Distance-measuring technology using LD for auto anti-collision

Auto anti-collision technology is one of the main research subjects of automobiles‘ safety technology. Aiming at the key technology of Auto anti-collision, measuring the distance from obstacles, based on the theory of phase laser distance ranging, Laser Diode (LD) distance-measuring system for auto anti-collision has been developed to solve the problem of on-line measuring distance technology in middle to long distance utilizing the good characteristics of LD when modulating its optical intensity and adopting typical kinds of filter techniques in this paper. By theoretical analysis, adopting typical kinds of filter techniques can reduce the interference of strong light, so distance-measuring range can be 0. 5-100 m in daytime or 1-200 m at night. And more, from theoretical analysis and experiment result, it can guarantee the high measuring resolution which can be less than 24. 5 mmutilizing the method of two Laser Diode optical intensity modulating wavelength and complimenting precise calibration and revision. The idea of LD distance-measuring technology is novel and feasible and this technology can be applied in Auto anti-collision.     

Rapid framing mass storage system on the internet

Mass storage system is now very important for storing huge volume of data in many application system such as VOD systems, electronic library, scientific computation and so on. Besides the storage device and network devices, the real performance of mass storage system is greatly influenced by the connection way between the host and storage system. Here we propose a new design of mass storage system by promoting the storage devices' functions and involving, them directly into data delivering. It can easily meet the demands both for capacity and I/O bandwidth in those applications, and has better service quality and performance compared with the traditional system in delivering mass data over network. Foundation item: Supported by the National Natural Science Foundation of China under grant (69973017) and Defense Advanced Research Foundation of China under grant (98J15. 1. 1. JW0520) Biography: Wang Fang(1972-), female, Ph. D candidate, research interest: mass storage system.     

新型掺杂稀土离子的可调谐激光晶体特性及应用

固体可调谐激光器在科学研究、医学、测量学、测试技术、超快脉冲激光器以及通讯等领域有着广泛的应用。其核心部件为可调谐激光晶体,晶体的物理性质和光学性质直接决定了激光器的性能。本文报道了以稀土离子为掺杂介质的新型可调谐激光晶体的光谱特性、激光特性及研究进展。     

Active optical clock

This article presents the principles and techniques of active optical clock, a special laser combining the laser physics of one-atom laser, bad-cavity gas laser, super-cavity stabilized laser and optical atomic clock together. As a simple example, an active optical clock based on thermal strontium atomic beam shows a quantum-limited linewidth of 0.51 Hz, which is insensitive to laser cavity-length noise, and may surpass the recorded narrowest 6.7 Hz of Hg ion optical clock and 1.5 Hz of very recent optical lattice clock. The estimated 0.1 Hz one-second instability and 0.27 Hz uncertainty are limited only by the relativistic Doppler effect, and can be improved by cold atoms. Supported by the National Basic Research Program of China (Grant No. 2005CB724500) and National Natural Science Foundation of China (Grant No. 10874009     

新型掺杂过渡金属离子可调谐激光晶体研究的现状与展望

固体可调谐激光器在科学研究、医学、测量学、测试技术、超快脉冲激光器以及通讯等领域有着广泛的应用。其核心部件为可调谐激光晶体,晶体的物理性质和光学性质直接决定了激光器的性能。常见可调谐激光晶体的掺杂离子分为两类,稀土离子和过渡金属离子。综述性报道了以过渡金属离子掺杂介质的新型可调谐激光晶体的光谱特性、激光特性及其近期应用进展。     

The effect of laser irradiation on surface enhanced raman scattering for silver film

The laser irradiation effect on the SERS intensity for Ag film is discussed using crystal violet (CV) as a probe. The thickness of silver film, the etching time of the glass slide by gaseous hydrogen fluoride, and the laser irradiation time for different amounts of CV on silver films were investigated. The laser burn-out model was proposed to explain the dependence of the SERS intensity of CV on the laser irradiation time. Supported by the National Natural Science Foundation of China Sheng Rongsheng: born in Dec. 1935, Professor     

1.55 μm wavelength operation of E r 3+ -doped optical fiber bistability

An all-optical all-fiber optical bistability operation has been realized in an all-fiber cavity consisted with Er-doped fiber and optical fiber-loop miroors. The experimental bistability threshold is consistent with the theory. Foundation item: Supported by the National Natural Science Foundation of China (69487007) Biography: Song Qian (1937-), female, Professor. Research direction: nonlinear optics and all-optical communication.     

光盘存储技术,产品和市场的发展（下）

本文介绍了在与磁存储技术对比和竞争中各种光盘存储技术的发展，从家用小型光盘系列到专业用数字光存储系统，分析了今后光盘存储技术的发展方向，主要为提高光盘存储密度和数据传输速率，以及需要解决的关键技术问题，并列出了可能发展途径，介绍了光盘技术市场的发展状况，指出它是多媒体技术系统中的主要介质，将成为光电子技术领域中最主要的产业之一。     

A Disk Scheduling Algorithm： SPFF

We put forward an optimal disk schedule with n disk requests and prove its optimality mathematically.Generalizing the idea of an optimal disk schedule, we remove the limit of n requests and, at the same time, consider the dynamically arrival model of disk requests to obtain an algorithm, shortest path first-fit first （SPFF）. This algorithm is based on the shortest path of disk head motion constructed by all the pendent requests. From view of the head moving distance, it has the stronger glohality than SSTF. From view of the head-moving direction, it has the better flexibility than SCAN. Therefore, SPFF keeps the advantage of SCAN and, at the same time, absorbs the strength of SSTF. The algorithm SPFF not only shows the more superiority than other scheduling polices, but also have higher adjustability to meet the computer system＇s different demands.     

Absorptive nonlinearity in Er-doped optical fiber

Optical absorptive nonlinearity in Er-doped optical fiber has been discussed and measured at the window wavelength 1.55 μm for optical communications firstly. It is proposed that the mechanism of this absorptive nonlinearity is the induced absorption. The first order nonlinear absorptive coefficient and the imaginary part and the complex value of the third-order susceptibility at that wavelength are obtained from the measured absorptive nonlinearity. Foundation item: Supported by the National Natural Science Foundation of China (69487007) Biography: Song Qian (1937-), female, Professor. Research direction: nonlinear optics and all-optical communications.     

三维光数据存储的分析与计算

三维多层光折射数字存储是一种新型的高密存储技术,对于克服目前的光存储系统的容量限制具有很大的潜力。文章用埃瓦得球结构分析了此种存储方法的横向与纵向带宽,从而在空域内计算了存储的密度。存储容量可以达到1Tb/cm3,用于光通信系统中是可行的;根据该存储系统在更深层聚焦时产生的球差,提出了一种全息校正装置。     

Dispersive nonlinearity in Er-doped optical fiber

Optical dispersive nonlinearities in Er-doped optical fiber are discussed and measured at the third window wavelength 1.55 μm for optical communications firstly. The experimental method, which is developed by us, is based on dynamic scanning for fixed-point-interference (DSFPI) of two fiber beams. The real part and complex value of the third-order susceptibility at the wavelength are also obtained from the measured Kerr coefficient and nonlinear-absorption coefficient reported elsewhere. Foundation item: Supported by the National Natural Science Foundation of China(69487007) Biography: SONG Qian(1937-), female, Professor. Research direction: nonlinear optics and all-optical communications.     

纳米CuCl晶簇室温光吸收谱

实验测定了平均尺寸４．２ｎｍＣｕＣｌ晶簇的室这紫外和可见光吸收谱线，给出了Ｈｅ－Ｎｅ激光束辐照下的光吸收谱线，在３．１８７ｅＶ处有宽度０．６２ｍｅＶ的吸收尖峰。     

Combined Viterbi detector for a balanced code in page memories

Based on the two path metrics being equal at a merged node in the trellis employed to describe a Viterbi detector for the detection of data encoded with a rate 6 : 8 balanced binary code in page-oriented optical memories, the combined Viterbi detector scheme is proposed to improve raw biterror rate performance by mitigating the occurrence of a twobit reversing error event in an estimated codeword for the balanced code. The effectiveness of the detection scheme is verified for different data quantizations using Monte Carlo simulations.     

激光火工品反射特性的高精度自动测试

激光火工品光窗口的反射特性是激光点火系统光路连续性检测的基础．文中针对目前激光火工品反射率测试精度低、速度慢等缺点,采用光分路方法和低功率窄脉冲测试技术研制出一种激光火工品反射率自动测试系统,该系统具有高安全性、高精度、高稳定度等特点,并能大幅度提高测试效率,对激光火工品的生产和应用具有重要意义．     

三维光数据存储技术

不断提高存储介质的存储容量和存储密度是信息科学的研究热点之一,在三维空间中进行数据存储将大幅度提高存储密度和存储容量,是实现超高密度光存储的有效方法。介绍了双光子吸收光存储、光谱烧孔光存储、激光全息存储和透明介质的飞秒脉冲体存储等三维光存储的进展、数据存储的原理以及各种存储方法有待解决的问题。     

Frequency synthesizer of short-wave SFH/MFSK system

The technology of DDS-driven PLL is introduced and a new scheme of frequency synthesizer which is suitable for SW SFH/MFSK System is presented in this paper. Based on the special requirement of SW communication, a model of the scheme is given and the results show that the frequency synthesizer has small frequency insteval (≤0.1 Hz), short switch pierod (<200 ms) and high frequency stability as crystal oseillator. Supported by the National Nature Science Foundation of China and the Advanced Research Foundation of National Defence Gan Liangcai: born in 1941, Professor     

Frequency synthesizer of short-wave SFH/MFSK system

The technology of DDS-driven PLL is introduced and a new scheme of frequency synthesizer which is suitable for SW SFH/MFSK System is presented in this paper. Based on the special requirement of SW communication, a model of the scheme is given and the results show that the frequency synthesizer has small frequency insteval (≤0.1 Hz), short switch pierod (<200 ms) and high frequency stability as crystal oseillator. Supported by the National Nature Science Foundation of China and the Advanced Research Foundation of National Defence Gan Liangcai: born in 1941, Professor     

PDM-CO-OFDM中采用相位传递的次符号光相位噪声抑制算法

在符号周期-光源线宽乘积较大的PDM-CO-OFDM系统中,光相位噪声引入的子载波间串扰(ICI)极大地劣化了系统的性能.采用高阶调制格式(如16QAM)的PDM-CO-OFDM系统对光相位噪声的敏感度随调制格式的升高而增加.针对上述受光相位噪声影响较大的系统,该文提出一种采用线性插值、相位传递和符号分割的光相位噪声抑制算法,即P-LI-SCPEC.推导了算法的数学模型,通过蒙特卡洛仿真研究了该算法的性能,并与已有的几种光相位噪声抑制算法进行了横向对比.仿真结果表明,该算法能有效地抑制光相位噪声,提高系统对光源线宽的容忍度,其性能优于此前提出的LI-SCPEC算法.该算法对于PDM-CO-OFDM技术在采用廉价光源的光接入网及采用高阶调制格式的主干网中的应用都具有重要的意义.