求高人解答：Dry pump,cryo pump,TMP的区别及各自的优缺点，谢谢！

pumping区别来说，根据性能不同，Dry pump 只能抽低真空，从标准大气压抽到10的负一次方，价格便宜，不过为了速度及TIME一般需要多台一起运行。cryo pump 冷凝泵，可以抽高真空，一般为了性能及能效，需要配合先用Dry pump抽到低真空然后再cryo pump 启动来抽到高真空，可以抽到10的负五次方，价格贵。TMP pump的话是抽超高真空的，可以达到10的负十二次方超高真空，价格肯定是更贵的。看需要的真空环境选用pump

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.

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