(n) electrical conductor
半导体 [bàn dǎo tǐ]
semiconductor
绝缘体 [jué yuán tǐ]
insulator
nonconductor
dielectric
isolator n.
Also known as laser diode laser diode (LD). Into the 1980s, it absorbed the physical development of the semiconductor up-to-date results, the use of quantum well (QW) and strained quantum well (SL-QW) structures, such as novelty, the introduction of the refractive index modulation Bragg launchers, as well as to enhance Bragg modulation transmitter The latest technology, as well as the development of the MBE, MOCVD and the CBE, such as crystal growth technology of the new technology, making new epitaxial growth technology to precisely control crystal growth to the accuracy of atomic layer thick, high-quality growth of quantum wells, as well as strained quantum well materials. As a result, production of the LD, the current threshold of a significant decline in conversion efficiency has been greatly improved the power output doubled, significantly longer service life.A low-power LD
In the field of information technology for the rapid development of low-power LD. For example, for fiber-optic communications and optical switching systems distributed feedback (DFB) and the dynamic single-mode LD, narrow linewidth tunable DFB-LD, such as CD-ROM for information processing technology in the field of visible light Wavelength (such as wavelength of 670nm, 650nm, 630nm The blue-green to red) LD, surface-emitting quantum well, as well as ultra-short laser pulses substantive, which are all treated the development of LD. The development of these devices are: narrow-linewidth single-frequency, high-speed, as well as short-wavelength tunable optical and integrated single-chip, and so on.
B high-power LD
In 1983, a single wavelength of 800nm output power LD more than 100mW, to 1989, 0.1mm-wide LD be reached 3.7W continuous output, and 1cm linear array LD has reached 76W output, the conversion efficiency of 39%. In 1992, the Americans also targets to a new level: 1cm linear array LD CW output power up to 121W, the conversion efficiency of 45%. Now, the output power of 120W, 1500W, 3kW and many other high-power LD have been published. High-efficiency, high power LD array and its rapid development for all-solid-state laser, diode laser that is pumped (LDP) of the rapid development of solid-state laser provides strong.
In recent years, in order to adapt to the EDFA and the EDFL, and other needs of the wavelength of 980nm high-power LD is that there is great development. Fiber Bragg Grating with recently selected frequency for filtering, a significant improvement in the stability of its output, pump effectively improve the efficiency.
And the characteristics of the application: semiconductor diode laser is the most important practical for a class of lasers. Its small size, long life, and a simple injection of current-pumped his way to work with the voltage and current circuit-compatible, which can be integrated with a single. And also can be as high as GHz frequency modulation direct current for high-speed modulation of laser output. As a result of these advantages, the semiconductor diode laser in the laser communications, optical storage, optical gyros, laser printing, as well as radar range, and so on, as well as access to a wide range of applications.
ILD有4个涵义:1.注入型激光二级管(Injection laser Diode)
又称p-n junction laser,半导体结型二极管激光器。是较成熟、较常用的一类半导体激光器,于1962年首次研制成功。
它的主体是一个正向偏置的p-n结,当电流密度超过阈值时,注入载流子(电子和空穴)在p-n结结区通过受激辐射复合,产生激光。其工作特性和输出特性受温度影响极大,故备有冷却系统。最早的同质结型砷化镓(GaAs)半导体激光器,在一块经过加工的砷化镓单晶体的上、下两面上(p型与n型砷化镓)分别焊上电极,组成谐振腔的两端面要平行,并经过研磨抛光,甚至涂膜,以增加反射,也可以直接利用平行的平坦晶面(自然解理面)组成谐振腔。砷化镓的折射率约为3.6,在半导体与空气的分界面上反射率高于30%,因此,它可提供光反馈作用,使激光振荡能够产生,激光波长约为9040Å。
可用在雷达、计算机及通信系统中,或用作视频唱片和声频唱片的光源,它在超高分辨率光谱学、集成光学以及军事等方面有着广泛的应用。
2.指示逻辑图表(instructional logic diagram)
3.德语 Ich Liebe Dich(I Love You,我爱你) 的缩写
4.间质性肺疾病(interstitial lung disease)
间质性肺疾病(ILD)是以弥漫性肺实质、肺泡炎症和间质纤维化为病理基本病变,以活动性呼吸困难、X线胸片弥漫性浸润阴影、限制性通气障碍、弥散(DLCO)功能降低和低氧血症为临床表现的不同种类疾病群构成的临床-病理实体的总称。
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