【正文】 由以上分析可以看出，產生激光必須具有以下條件（圖 ） 圖 固體激光器 （1）激活介質 即通過外界激勵能實現粒子數反轉和發(fā)射出激光的物質體系，也稱激光工作物質或增益介質。上面定性地描述了激光的產生過程。處于亞穩(wěn)態(tài)能級上的粒子越多，則光放大就越強[2]。ν=E2——E1 的外來光子或其他相同能量的誘發(fā)源的作用，在亞穩(wěn)態(tài)能級 E2 上所積累的粒子就躍遷到 E1 能級并發(fā)射出與誘發(fā)光子同樣性質（即頻率、相位、偏振、傳播方向相同）的光子。如果外界激勵能量足夠強，就可以使處于高能級（亞穩(wěn)態(tài)能級）上的粒子數目大于處于低能級的粒子數目，粒子的這種分布狀態(tài)與前面所說的正常分布相反而稱為粒子數反轉或反分布。自發(fā)輻射是的重要特征是具有隨機性，發(fā)射出的光子的頻率大小，傳播方向和步調都不一樣，毫無規(guī)律，故自發(fā)輻射的光是各種波長光子的無序組合，是方向性、單色性差的非相干光，例如普通電燈、日光燈、高壓水銀燈等發(fā)射出來的光。[1] 兩個能級距離相差越大，頻率就越高，波長就越短。當粒子受到外界的激勵（如光、電、熱、化學等） ，吸收了外來的能量，就會由低能級躍遷到高能級，粒子在激發(fā)能級的平均停留時間（稱為壽命）是很短的，總是力圖躍遷到較低的能級上（例如躍遷到 E2 能級上） ，在此過程中將多余的能量以光子的形式（也有熱或其它形式的）自發(fā)的釋放出來。在通常條件下，絕大多數粒子是處在能量最低的能級 E1 上（稱為基能級） ，處于比基能級高的能級（稱為激發(fā)能級）的粒子也比較少的。激光的問世，標志著人類掌握和利用光現象已進入了一個新階段，是繼量子物理學、無線電技術、原子能技術、半導體技術、電子計算機技術之后的又一重大科學技術新成就。1960 年美國 界上第一臺紅寶石激光器，向全世界宣告了激光的誕生。英文名稱是 Laser，中文意思是受激輻射產生的光放大。 主要內容有： 光電聲磁的物理特性及與物質的相互作用效應（尤其是生物效應）與機理。 實踐證明，在這方面的成功應用，可開發(fā)出一系列高層次的新技術、新工藝、新產品、新設備，帶來十分巨大的經濟效益和社會效益。AbstractPulse discharge in the liquid medium in the use of the biological effectiveness of pulse discharge similar sterilization is the most active of a physical sterilization technology. Liquids pulse discharge sterilization equipment, generally by the two major ponents: First,the supply of energy pulse discharge power, and the other liquid material directly to the sterilization of sterilization room. Figure is a pulse discharge of the principle of sterilization equipment, including sterilization room from two different diameter of the “drums” posed. They were to supply the positive and negative, the liquid material from below the population inflow. After the gap between them from the upper outflow of exports. In the process of plete mobile sterilization process. Ultrasound in solid, liquid and gas transmission, because the interaction between ultrasound and media so that the media in the physical and chemical change, resulting in a series of mechanical, thermal, chemical and electromagic effects of ultrasound, the ued of these effects can affect and chang the material that destroyed the status, nature and anization structure. In particular, the role of ultrasound in a low voice strong case, the effect is reversible, and the sound intensity over a certain threshold will have irreversible effects. These have the effect of law, control their conduct, can be expected to achieve a certain objective of the process, sterilization is the use of ultrasound to the effect of ultrasound biological, physical and chemical effects. Study found that in the presence of air or other gas liquid, in the ultrasonic radiation, mainly due to the strong air of the effective role of mechanical damage and kill certain bacteria and viruses, or to lose toxicity. Ultrasound is the ultrasound both of the main tools scattered by the ultrasonic generator, ultrasonic vibration systems, ultrasound scattered tools, containers scattered ponents. Both of the working principle, when the ultrasonic generator output voltage and high frequency of the ultrasonic vibration, the vibration of horn after mechanical amplitude Larger Role in scattered tools, in containers within a strong decentralized.Key word: pulse discharge, ultrasonic sterilization, both of ultrasound Food sterilization technology is the industry one of the core technology, with the rapid development of science and technology, using ultrasonic pulse disinfection and sterilization in people’s lives of more and more widely, but the present, we have on the one hand. aso very limited. Thus it is a vigorous development and there are unlimited prospects for the technical and industrial fields. As an emerging filed, it must be a lot of room for development, it will move more highprecision positioning in the direction of, to meet the growing needs of the munity. At present, the most extensive application of this technology for liquid is sterilized, ultrasonic pulse discharge of the unique properties of water, food, such as sludge treatment and greatly improve the daily life of the inconvenience, but also reduces certain industries. The waste of energy and opens up good prospects. In industrial production, ultrasonic pulse sterilization and disinfection to play the same role can not be ignored, such as: ultrasonic sterilization technology for small static cleaning the boiler. Pulse sterilization can be applied effectively killed the wine and soy sauce in most of the bacteria, is used in industrialscale production of wine and soy sauce on the role played great. Although this technology in China also start soon, the current technology has yet to be improved, but we can see its future and prospects, the use of modem science and technology, we can improve the technology so that it more closely with the Automation, embodied economy. In the new century, Miamaoyixin the ultrasonic pulse sterilization technology and sterilization technology will play a greater role.Key word: ultrasonic wave sterilization Pulse sterilization In the 21st century, along with high technology and new technology and so on electron, information unceasing development, along with the market demand personalization and the diversification, in the future the advanced laser and the ultrasonic wave technological development’s general trend will be to the precisonic , the flexibility, the work, the virtualization, intellectualized, the clear purification, integrated, the globalized direction develops. Especially in food fermentation industry. This is because the laser characteristic and the ultrasonic wave transmission characteristic and has the cavitation to maintain freshness, and so on a series of transformation effect, enables it to have in the following several aspects further studies and applies: laser stimulating surface reation of methanol on oxide pounds Reaserch on Exogenous DNA Introduction in Vegetable Breeding Analysis of fructose, gloucose,