发光二极管的研究现状与发展趋势

Ⅱ－Ⅵ族，Ⅲ－Ⅴ族化全物半导体是制作显示器件的重要材料，随着制作工艺日趋成熟，发光二极管已广泛地应用于 民经济各部门。要方要介绍了国内外发光二有管的研究两头和发展趋势。     

耦合腔激光器的波长调谐与频率调制特性分析

考虑用激光器与调制器直接耦合以及耦合槽的影响，用散射矩阵法及二步等效反射率法，对沟槽耦合腔激光器的波长调谐和频率调制特性的分析表明，数学处理简单，物理图像清晰。     

Anomalous capacitance of quantum well double-barrier diodes

The S-parameters of several different quantum well double barrier diodes have been measured. A technique has been developed for measuring whisker contacted diodes with and HP 8510B automatic network analyzer. Special coaxial mounts using K-connectors were designed to enable measurements up to 20 GHz. The voltage-dependent conductance and capacitance were derived from the measured reflection coefficient of each device. The C/V characteristics were observed to exhibit an anomalous increase at voltages corresponding the the negative differential resistance region (NDR). These are the first reported S-parameter measurements in the negative differential resistance region of quantum well double barrier diodes. A theory is presented that explains, in part, the observed results.     

10W QCW operation of a proton implanted GaAlAs diode laser array

We report one thick layer of hard-baked photoresist mask.The laser array stripe pattern was defined by standard wet lithography.With this mask, a 10 W QCW(quasi-continuous wave) operation of a narrow proton implanted multiple stripe conventional single quantum well separate confinement heterostructure(SQW-SCH) GaAlAs diode laser array has been realized.These devices exhibit the lateral far-field radiation pattern of a phase-locked array of gain-guided semiconductor injection laser array. The twenty stripe laser array has a lateral far-field beam divergence full width at half maximum (FWHM) of less than 3°, and three twenty stripe laser array has a beam divergence in the plane of the junction of about 9°.     

220GHz 次谐波混频器设计

本文介绍了一种基于平面肖特基势垒二极管的220GHz 次谐波混频器的设计。该混频器采用Teratech 公司的反 向并联二极管对,安装在0.05mm 厚的石英基片悬置微带上。采用HFSS 和ADS 联合仿真,使得混频器在射频频率为 215GHz~225GHz 范围内仿真所得变频损耗低于8dB,并在219GHz 时取得最佳变频损耗6.75dB。该混频器具有结构简单, 易于加工,变频损耗低的优点。     

Qualification of plastic encapsulated microcircuits (PEM) for avionicsBased on ``Plastic Encapsulated Microcircuits (PEM) Qualification Testing'''', by J. A. Scalise, which appeared in the Proceedings of the 46th Electronic Components and Technology Conference, Orlando, FL, U.S.A., 28–31 May 1996, pp. 392–397. © 1996 IEEE.

Microcircuit package qualification testing is used to establish the reliability of integrated circuit processes and devices as they relate to part packaging. This paper presents the results of package qualification tests conducted on plastic encapsulated microcircuits (PEMs) and plastic discrete devices (diodes, transistors) used in avionics applications. Highly accelerated stress test (HAST) and temperature cycle (TC) test results, including part failure mechanisms and associated failure rates, are provided. A variety of plastic package styles and integrated circuit functions have been tested. Examples of package styles tested include small outline (SO), plastic leaded chip carrier (PLCC), thin small outline package (TSOP), plastic quad flat package (PQFP) and plastic dual-in-line (PDIP).Manufacturers' devices have been evaluated and various plastic compounds have been compared to determine which provide optimum reliability. The testing showed that package qualification performance of PEMs is affected by type of compound, passivation (including die coat) and die size. HAST failures are caused by moisture penetration of the package while temperature cycle failures result from coefficient of thermal expansion (CTE) mismatch effects.     

可见光激光二极管开发现状与市场——市场状况

本文是可见光激光二极管开发现状与市场的最后部分,主要介绍器件应用领域,产销量,价格与趋势.     

Optical Fiber Pressure Sensor with Reference channel^①

The principle of optical fiber pressure sensing probe with common diaphragm and the method for stabilizing the laser diodes are described in this paper at first.Then we discussed the improvement in characteristics of the system by means of taking the techniques of reference light channel and ratio measurement.     

固体激光泵浦用激光二极管开发现状

文中介绍固体激光泵浦用激光二极管的特点、结构、研制的产品水平,及其发展趋势。     

Boron-Dipyrromethene-Based Fluorescent Emitters Enable High-Performance Narrowband Red Organic Light-Emitting Diodes

Narrowband organic light-emitting diodes (OLEDs) are receiving significant attention and have demonstrated impressive performance in blue and green OLEDs. However, developing high-performance narrowband red OLEDs remains a highly desired yet challenging task. Herein, we have developed narrowband red fluorescent emitters by utilizing a boron-dipyrromethene (BODIPY) skeleton in combination with a methyl-shield strategy. These emitters exhibit small full-width at half-maxima (FWHM) ranging from 21 nm (0.068 eV) to 25 nm (0.081 eV) and high photoluminescence quantum yields (Φ_PL) ranging from 88.5 % to 99.0 % in toluene solution. Using BODIPY-based luminescent materials as emitters, high-performance narrowband red OLEDs have been assembled with external quantum efficiency as high as 18.3 % at 623 nm and 21.1 % at 604 nm. This work represents, to our knowledge, the first successful case of achieving NTSC pure-red OLEDs with the Commission Internationale de l’Éclairage (CIE) coordinates of [0.67, 0.33] based on conventional fluorescent emitters.