计算机输出光盘技术与全点可寻址文件

起初，当计算机输出光盘（ＣＯＬＤ）用来处理典型的行输出模式数据时，曾经是众者之王。打印在预印表格纸上的文件和常用的绿格报表，对ＣＯＬＤ系统而言很理想。如果贵公司对ＣＯＬＤ的需求很典型，有可能您已经使用了一段时间的ＣＯＬＤ。但如果贵公司需要能支持一种全...     

亚毫安室温连续工作InGaAs垂直腔面发射激光器

报道了ＩｎＧａＡｓ应变量子讲垂直腔面发射激光器（ＶＣＳＥＬ）的室温连续工作。在ＭＢＥ生长过程中利用红外高温仪测量了表观衬底热辐射振荡，实现了原位厚度监测；采用阶梯型分布布拉格反射器（ＤＢＲ）及腐蚀倒台面结构，降低了器件串联电阻。对于２×３μｍ２的台面结构ＶＣＳＥＬ，室温连续工作阈值电流一般为１．５ｍＡ，最低达到０．７ｍＡ，阈值电压为２．５伏，输出功率达到０．５ｍＷ，激射波长为０．９４ｕｍ，量子效率为１２％。     

烯基双酚A醚接枝LDPE的研究

介绍了烯基双酚Ａ醚（ＤＢＡＥ）在引发剂过氧化二异丙苯（ＤＣＰ）存在下，与低密度聚乙（ＬＤＰＥ）在Ｈａａｋｅ转矩流变仪的混炼器中进行熔融接枝反应的工艺。采用示差扫描量热仪（ＤＳＣ）、红外光谱（ＦＴ－ＩＲ）分析了接枝共聚反应和证实了接枝共聚物ＬＤＰＥ－ｇ－ＤＢＡＥ的结构。并通过正交实验及数据分析，确定了合成ＬＤＰＥ－ｇ－ＤＢＡＥ的最佳工艺条件。     

雅奇632LCD闪光灯

雅奇６３２ＬＣＤ闪光灯文澜雅奇（ＡＣＨＩＥＶＥＲ）６３２ＬＣＤ闪光灯是一款自动调光多功能专业闪光灯，是国产外插式单体闪光灯中的最高档产品之一，自动化程度高，供专业摄影用。６３２ＬＣＤ使用了Ｊ当今中高档照相机上已普遍采用的大液晶屏资料显示。显示内容包括...     

TECHNICAL AND ECONOMIC ASPECTS OF TUNNEL BLASTING ACCURACY CONTROL

ＴＥＣＨＮＩＣＡＬＡＮＤＥＣＯＮＯＭＩＣＡＳＰＥＣＴＳＯＦＴＵＮＮＥＬＢＬＡＳＴＩＮＧＡＣＣＵＲＡＣＹＣＯＮＴＲＯＬ￥ＲｅｎａｔｏＭＡＮＣＩＮＩ（）；ｖａｎｎｔＢＡＤＩＮ０（）；ＮｉｃｏｌａＩＮＮＡＵＲＡＴ０（＊）；ＭａｕｒｏＦＯＲＮＡＲ０（＊），Ｍ...     

SIGMA—DELTADAC板的设计技术

介绍了一种新型的ＤＡＣ板──ＳＩＧＭＡ－ＤＥＬＴＡ ＤＡＣ的设计技术,给出了ＤＡＣ板的设计原理框图,详细叙述了ＳＩＧＭＡ－ＤＥＬＴＡ ＤＡＣ的硬件设计及软件调试结果。     

REPORT ON ELECTROMAGNETIC METROLOGY IN CHINA DURING 1990-1992

ＲＥＰＯＲＴＯＮＥＬＥＣＴＲＯＭＡＧＮＥＴＩＣＭＥＴＲＯＬＯＧＹＩＮＣＨＩＮＡＤＵＲＩＮＧ１９９０－１９９２￥ＹａｎｇＸｉａｏｒｅｎ；ＲｅｎＤｉａｎｑｉｎｇ；ＬｉＺｉｚｈｏｎｇ（ＣｏｍｍｉｓｓｉｏｎＡ，ＣｏｍｍｉｔｔｅｅｆｏｒＣｈｉｎｅｓｅＵＲＳＩ）...     

固相法CPE增容PVC／LDPE共混体系的研究

通过力学性能试验、动态力学分析（ＤＭＡ）、电子显微镜观察，研究了固相法氯化聚乙烯（ＣＰＥ）对聚氯乙烯（ＰＶＣ）与低密度聚乙烯（ＬＤＰＥ）共混体系的增容作用。实验结果表明，ＣＰＥ的加入能明显改善ＰＶＣ／ＬＤＰＥ共混体系的相容性，显著提高共混物的力学性能，且低温氯化制得的ＣＰＥ的改善效果优于两段氯化制得的ＣＰＥ。电子显微镜观察表明，增容剂增加了共混体系相间相互作用或相界面粘附性，对共混体系的形态结构产     

回转体零件CAD／CAPP／CAM集成系统的研究与开发

本文阐述了北京第一机床厂在ＣＩＭＳ环境下，通过对零件特征的分析，提出了一种实用的描述产品零件的方法，在此基础上实现了回转体零件的ＣＡＤ／ＣＡＰＰ／ＣＡＭ集成系统的开发。重点论述了该系统的总体框架设计和主要功能：ＣＡＤ特征定义及描述；基于商品ＣＡＤ软件ＩＣＥＭＤＤＮ之上的特征造型；应用通用专家智能系统开发工具，建立工艺知识模型及推理系统；经相应的后置处理实现ＮＣ程序的自动生成及以ＯＲＡＣＬＥ。ＥＤＬ     

继续教育与人才

继续教育与人才谢荣全，刘晓玫ＣＯＮＴＩＮＵＡＴＩＯＮＥＤＵＣＡＴＩＯＮＡＮＤＴＡＬＥＮＴＥＤＰＥＯＰＬＥ￥ＸｉｅＲｏｎｇｑｕａｎ；ＬｉｕＸｉａｏｍｅｉＡｂｓｔｒａｃｔ：Ｅｘｐｌａｎａｔｉｏｎｓｆｏｒｔａｌｅｎｔｅｄｐｅｏｐｌｅａｒｅｖａｒｉｏｕｓ．Ｂ...     

Tuning of external-cavity semiconductor lasers with chirped diffraction gratings

We present a novel scheme of tunable semiconductor laser based on the use of a chirped grating in an external cavity. The chirped grating is fabricated using a simple holographic technique: two Gaussian beams having wavefronts with different radii of curvature are brought to interfere on a photoresist layer. The tuning properties of chirped gratings have been investigated with semiconductor lasers operated with an external cavity. With this type of grating positioned in Littrow configuration, the wavelength selection can be done by translating the grating without any need to rotate it. This cavity configuration provides a tunable output beam with an angle of propagation that is independent of the wavelength. The translation of chirped gratings was shown to tune a visible diode laser and an infrared diode laser over the same spectral band as the conventional tuning scheme where an unchirped grating is rotated.     

Wavelength-tunable semiconductor pump diode for reconfigurable Raman amplification

We demonstrate a wavelength-tunable semiconductor pump diode for Raman amplification. Thediode is stabilized by a fiber Bragg grating (FBG) that can be continuously tuned over more than 20 nm. Tuning of the diode output wavelength is achieved by varying the center wavelength of the FBG, since the diode preferentially lases within the FBG bandwidth. We investigate the effects of wavelength tuning on the diode spectrum on its corresponding Raman gain, and on pump-pump four-wave mixing in fiber having zero-dispersion wavelength coincident with the Raman pumps.     

Application of novel azo metal thin film in optical recording

The absorption spectrum of spin-coated azo metal thin film showed a comparatively large absorption band in the wavelength region (500–600 nm), which matched with the wavelength of the GaAlInP semiconductor diode laser (630–650 nm). The optical recording performance of the film was investigated.     

室温准连续多量子阱二极管激光器调谐特性

为了将应变补偿多量子阱（SC-MQW）激光器用于调谐激光吸收光谱（TDLAS）技术进行气体分子检测,研究了SC-MQW激光器在室温、准连续工作模式下的调谐特性.从半导体激光器的速率方程出发,分析了SC-MQW激光器输出波长与温度和注入电流的关系;使用傅里叶变换红外光谱仪（FT-IR）测量了激光器分别在不同电流、温度条件下的调谐特性,得到SC-MQW激光器在允许工作电流范围内的调谐范围接近20nm,电流调谐率约为0.03nm/mA;温度调谐率约为0.25nm/℃;电流和温度联合调谐的波长覆盖范围达50nm.结果表明,该激光器在带状吸收谱的挥发性有机物气体检测方面有很好的应用前景.     

Spectral characteristics of a regenerative semiconductor optical amplifier mutually injection locked with a Fabry-Perot laser diode

The anomalous injection locking of a traveling-wave semiconductor optical amplifier (SOA) and a fiber-pigtailed Fabry-Perot laser diode (FPLD) linked with single-mode and improved side-mode suppression ratio output is demonstrated. We achieve this injection locking by driving the FPLD slightly below threshold and by feedback injecting the FPLD with fractional output of a closed-loop SOA. The SOA-FPLD link lases in a single FPLD longitudinal mode with a reduced linewidth of 0.013 nm and a maximum side-mode-suppressing ratio of 39.7 dB. A precise 3-dB linewidth of 45-50 MHz is also observed from the self-homodyne mode-beating spectrum. The optimized feedback-injecting power for the FPLD is approximately 2% of the SOA-FPLD linked output power of >400 microW. The variations in output power and in peak wavelength are not more than 0.54% and 0.06%, respectively. The injection-locked SOA-FPLD link is insensitive to the temperature fluctuation within +/- 0.25 degrees C.     

High-power semiconductor radiation sources based on 100-W diode laser bars for pumping solid-state lasers

High-power semiconductor radiation sources with a total optical output power of up to 5 kW and a power density of 400 W/cm² have been developed, representing a vertical stack of quasi-continuous pulsed (500 μs) 100-W diode laser bars. Based on such sources, a solid-state laser with an output radiation energy of up to 150 mJ has been created, which is intended for information systems, laser radars, spectrum analyzers, etc.     

Tunable output power varying with the splitting ratio of a coupler from a fiber ring semiconductor laser

The tunable output power characteristics of a fiber ring semiconductor laser have been studied by use of rate equations. An expression for the tunable output power is deduced. The analysis confirms that there is an optimum coupler splitting ratio to trade off between wavelength tuning width and output power.     

Wavelength control of tunable dense wavelength-division multiplexing sources by use of a Fabry-Perot etalon and a semiconductor optoelectronic diode

A high-resolution tunable-wavelength controller is achieved by use of an etalon for control of wavelength drift and a semiconductor optical diode (SOD) for channel recognition. The etalon provides a stable wavelength reference, and the SOD can detect mode-hopping and incomplete-tuning problems in tuning a laser. With the help of a Fabry-Perot etalon as a precise wavelength reference, the usual concern with the temperature stability of a SOD can be relaxed at least tenfold compared with wavelength control with a single SOD. We demonstrate the feasibility of monitoring tunable lasers by using a Fabry-Perot laser diode (FPLD) or a semiconductor optical amplifier (SOA). The induced voltage of the FPLD and that of the SOA are modeled with analytic expressions that can help to optimize the operation of a SOD sensor.     

Frequency stabilization of a 1.3 microm laser diode using double resonance optical pumping in the 5P 3/2-6S 1/2 transition of Rb atoms

The frequency stabilization of a laser diode in the 1.3 microm region using double resonance optical pumping (DROP) spectrum in the 5P(3/2)-6S(1/2) transition of (87)Rb atoms is demonstrated. The signal-to-noise ratio of the DROP spectrum is approximately ten times higher than that of the previous optical-optical double resonance spectrum. The spectral linewidth of the DROP measures 8.4 MHz. When the frequency of a 1.367 microm laser diode is stabilized to the DROP spectrum, the frequency stability is 9 x 10(-12) after 100 s. Also, the wavelength of the frequency-stabilized laser locked to the 5P(3/2)-6S(1/2) transition using a wavelength meter is measured.     

High-resolution random-modulation cw lidar

A high-resolution random-modulation continuous wave lidar for surface detection using a semiconductor laser diode is presented. The laser diode is intensity modulated with the pseudorandom binary sequence. Its enhanced resolution is achieved via interpolation and a novel front-end analog technique, lowering the requirement of the analog-to-digital converter sampling rate and the associated circuitry. Its mathematical model is presented, including the derivation of the signal-to-noise ratio and the distance standard deviation. Analytical and experimental results demonstrate its capability to achieve distance accuracy of less than 2?cm within 2.6?ms acquisition time, over distances ranging from 1 to 12?m. The laser diode emits 1.4?mW of optical power at a wavelength of 635?nm.