半导体激光器驱动电路设计

为了提高半导体激光器(LD)的使用寿命,确保激光器发射信号的质量,设计了一款高性能、低成本的激光驱动电路,包含慢启动电路、恒流电路和保护电路三部分。在TINA环境下进行模拟,结果显示该驱动电路满足设计需求,对类似电路设计有很好的借鉴作用。     

Effect of slaughter season on fatty acid composition, conjugated linoleic acid isomers and nutritional value of intramuscular fat in Barrosã-PDO veal

This paper describes the influence of slaughter season on lipid content, fatty acid composition, conjugated linoleic acid (CLA) isomeric profile and nutritional value of fat in Barrosã veal from calves reared according to the specifications of the Protected Designation of Origin (PDO). Barrosã purebred calves (n = 27) were raised in a traditional production system and slaughtered in early autumn (October) and late spring (June). Barrosã-PDO veal only presented seasonal differences in the levels of some minor fatty acids and CLA isomers, as well as in the PUFA/SFA ratio. Based on the analysed grass intake indicators, it was shown that veal-PDO has similar values to pasture-fed cattle for both slaughter seasons. From a human nutrition perspective, intramuscular fat in Barrosã-PDO veal has a high nutritional value throughout the year, since CLA contents and the percentages of the c9,t11 isomer are relatively high, and the n − 6/n − 3 ratios are within the recommended values for the human diet.     

Growth and optical device evaluation of P-type conductive lec gaas Co-doped with in and zn

Dislocation-free and low dislocation densityp-type conductive GaAs crystals 50 mm in diameter were successfully grown by the In and Zn co-doping LEC technique. They were evaluated through the characterizing of LEDs and LDs fabricated on them with epitaxial films grown by the conventional LPE process. The properties of LEDs fabricated on a co-doped substrate with an In concentration of 1 × 10²⁰ atoms/cm³ were inferior to those fabricated on a boat-grown substrate, even though the co-doped substrate was dislocation-free. On the other hand, the properties of LEDs and LDs on a co-doped substrate with an In concentration of 2 × 10¹⁹ atoms/cm³ were somewhat superior to those fabricated on a boat-grown substrate. There seems to be a particular In concentration in a GaAs substrate which is the most suitable for application to optical devices containing epitaxial AlGaAs film.     

LD泵浦Nd:Gd0.42Y0.58VO4/Cr4 :YAG被动调Q锁模激光器

报道了一种激光二极管（LD）泵浦Nd：Gd0.42Y0.58VO4/Cr^4＋：YAG/KTP结构的被动调Q锁模绿光激光器,采用简单、结构紧凑的平凹腔设计.在注入泵浦功率7.8 W时,调Q锁模绿光平均输出功率为200 mW,调制深度约为40%,脉冲包络重复频率200 kHz,半高宽度100 ns.     

一种LD侧面抽运固体激光棒光线追迹的数值计算

介绍了一种LD侧面抽运固体激光棒光线追迹的数值计算方法,并根据光线追迹公式编制了程序,画出了激光棒内光强的相对分布图。从光强的分布图可以看出,激光棒内光强的分布均匀。该程序使用方便、可行。     

适合LD泵浦的Tm:YAG的研究

研究了ＴｍＹＡＧ激光晶体的光谱特性，重点分析了适合ＬＤ泵浦的优越性和ＴｍＹＡＧ中ＯＨ根对激光性能的影响。     

LD泵浦高效多波长激光晶体：掺钕钨酸钾钆

本文综述了掺钕钨酸钾钆Ｎｄ＾３＋＂ＫＧｄ（ＷＯ４）２晶体制近况，介绍了其晶体结构，光谱特。Ｎｄ２ＫＧＷ晶体具有掺杂浓度高、泵浦阀值低，激光转移效率高的特性；强而宽的吸收谱线使该晶体适用于 二极管泵浦而无需温度控制。     

MOCVD生长1．06μm InGaAs／GaAs量子阱LDs

用低压MOCVD生长应变InGaAs/GaAs量子阱,采用中断生长、应变缓冲层(SBL)、改变生长速度和调节Ⅴ/Ⅲ等方法改善InGaAs/GaAs量子阱的光致发光(PL)质量。PL结果表明,10s生长中断结合适当的SBL生长的量子阱PL谱较好。该量子阱应用于1.06μm激光器的制备,未镀膜的宽条激光器(100μm×1000μm)有低阈值电流密度(110A/cm2)和高的斜率效率(0.256W/A,per.facet)。     

提高国产激光器组件直接调制速率与PIN－FET组件频响带宽的新技术

本文对如何提高国产１．５５μｍＩｎＧｒａＡｓｐＤＦＢ－ＬＤ组件直接高速调制速率以及国产ＰＩＮ－ＦＥＴ组件的频响带宽进行了理论与实验研究。在实验测量的基础上建立了国产ＬＤ组件小信号等效电路模型，对其调制响应速率的主要限制因素进行了分析，研制了高速ＤＦＢ－ＬＤ组件，将其调制速率提高到３．２ＧＨｚ。同时，在对谐振式ＰＩＮ－ＦＥＴ光接收机进行噪声分析的基础上，采用微波混合集成工艺研制了一个串联谐振式ＰＩＮ－ＦＥＴ光接收组件，有效地提高了ＰＩＮ－ＦＥＴ的频响带宽。     

1.3μm波长InGaAsP／InP脊形波导激光器

本文介绍用一次液相外延制备五层结构的晶体材料及自对准的工艺方法研制成功的１．３μｍＩｎＧａＡｓＰ／ＩｎＰ脊形波导（ＲＷＧ）结构的激光器。用有源区向上的装架方式，在２５℃时，激光器最小连续波（ＣＷ）阈值电流为２３ｍＡ，且均匀性较好；最大单面光电转换效率为０．１８ｍＷ／ｍＡ；在６５℃的环境温度下其最大发射功率仍大于１０ｍＷ；用标准单模光纤耦合，２５℃下阈值电流为２０ｍＡ的入纤光功率大于１．５ｍＷ。