本文關(guān)鍵詞： 半導(dǎo)體激光器 光纖耦合 光束整形 主動紅外　出處：《西安電子科技大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著安防領(lǐng)域的發(fā)展,智能視頻技術(shù)的不斷出現(xiàn),對夜間動態(tài)監(jiān)控的要求越來越高,在油田、礦山、景區(qū)、森林防火、交通工程、城市反恐等方面需要進(jìn)行夜間中遠(yuǎn)距離的跟蹤監(jiān)視。主動紅外夜視技術(shù)是通過光源主動照射目標(biāo),利用目標(biāo)反射光源的紅外線來實(shí)施目標(biāo)監(jiān)控的一種夜視技術(shù),產(chǎn)生這種不可見光的紅外光源,最常見的是陣列式LED燈,這種光源電光轉(zhuǎn)換率只有25%左右,多余的能量轉(zhuǎn)換成熱量,功耗很大,照射距離只有幾十米,無法滿足中遠(yuǎn)距離的監(jiān)控要求。而半導(dǎo)體激光器作為新一代的紅外光源,電光轉(zhuǎn)換率達(dá)到50%以上,而且發(fā)射的激光在方向性、單色性方面也是LED燈無法比擬的,這使得半導(dǎo)體激光器成為不同于LED燈技術(shù)的新一代紅外光源產(chǎn)品。本論文的研究目的是得到低成本、實(shí)用化的紅外半導(dǎo)體激光光源,采用不同的工藝,開發(fā)出不同功率的半導(dǎo)體激光光源,滿足現(xiàn)有的市場需求。優(yōu)化激光器封裝工藝,減少激光器芯片的熱阻,提高激光器芯片的壽命和性能。開發(fā)光纖、合束光纖的組裝、研磨和拋光工藝,使光纖端面滿足紅外半導(dǎo)體激光器耦合的要求。有了高可靠性的激光器芯片和高透過率的光纖、光纖束,就可以進(jìn)行光纖耦合和光斑勻化的工作。激光器光束是橢圓的高斯光束,光束的垂直發(fā)散角較大,其光斑由于有高階模式的存在而呈若干長條狀,光斑不均勻。激光器光束若直接用于照明,照明效果很差,必需對其進(jìn)行整圓和光斑均勻化處理。單個大功率激光器,目前常用方案是用兩個激光器經(jīng)過光學(xué)透鏡壓縮,重疊光斑,兩個激光器的光斑互補(bǔ)后,可將一些暗條紋變亮,以此來提高均勻性。本論文將提供另一種低成本實(shí)用化方案,使用光纖和光學(xué)勻化片,來解決光斑均勻性問題。同時,為了滿足幾公里這種遠(yuǎn)距離的監(jiān)控,激光光源采用列陣封裝,光斑經(jīng)過壓縮和光纖耦合后,使用多纖芯捆綁的方式輸出激光,其激光器輸出功率高,性能可靠,使用靈活,光斑均勻的效果更好；通過微光學(xué)元件對激光器的光束進(jìn)行整形、變換,再通過非球面透鏡聚焦耦合到單根光纖中,這種多單管空間耦合激光器的體積小,功率密度高,亮度高,光束質(zhì)量好�？梢詽M足特殊要求的紅外照明系統(tǒng)。最后,改進(jìn)光纖的對接方式,提高對接效率,使紅外激光器的輸出功率更高,在滿足光斑均勻性的同時,提高紅外激光器的照射亮度和照射距離。
[Abstract]:With the development of security field and the continuous emergence of intelligent video technology, the requirement of dynamic monitoring at night is higher and higher. In oil fields, mines, scenic areas, forest fire prevention, traffic engineering, Active infrared night vision technology is a kind of night vision technology that actively illuminates the target through the light source and uses the infrared ray of the target reflected light source to carry out the target monitoring. The most common source of infrared light that produces this invisible light is an array of LED lamps. The electro-optic conversion rate of this light source is only about 25%, the excess energy is converted into heat, the power consumption is very large, and the radiation distance is only several tens of meters. Semiconductor laser, as a new generation of infrared light source, has an electro-optic conversion rate of more than 50%. Moreover, the directionality and monochromaticity of the emitted laser is unparalleled by LED lamp. This makes semiconductor laser a new generation of infrared light source products different from LED lamp technology. The purpose of this paper is to obtain low cost, practical infrared semiconductor laser light source and adopt different technology. The semiconductor laser light source with different power is developed to meet the existing market demand. The laser packaging technology is optimized, the thermal resistance of the laser chip is reduced, the lifetime and performance of the laser chip is improved, and the assembly of optical fiber and bundled fiber is developed. Grinding and polishing process to make the optical fiber end surface meet the requirements of infrared semiconductor laser coupling. With high reliability of the laser chip and high transmittance fiber, fiber bundle, The laser beam is an elliptical Gao Si beam, the vertical divergence angle of the beam is large, and the spot of the laser beam has several long strips due to the existence of higher-order modes. If the laser beam is used directly for illumination, the illumination effect is very poor, so it is necessary to deal with the whole circle and the light spot homogenization. At present, the common scheme for a single high-power laser is to compress two lasers through optical lens. Overlap spot, two laser spot complementary, can brighten some dark fringes to improve uniformity. This paper will provide another low-cost practical solution, using optical fiber and optical homogenization, To solve the problem of spot uniformity. At the same time, in order to meet the remote monitoring of several kilometers, the laser light source is packaged in array. After compression and optical fiber coupling, the laser is output by multi-core binding. The laser has the advantages of high output power, reliable performance, flexible use and uniform spot. The laser beam is shaped, transformed and coupled to a single optical fiber by focusing through an aspheric lens. The multi-tube space coupled laser has the advantages of small volume, high power density, high brightness and good beam quality. It can meet the special requirements of the infrared illumination system. Finally, the docking mode of the optical fiber is improved and the docking efficiency is increased. The output power of the infrared laser is higher, and the illumination brightness and the irradiation distance of the infrared laser can be improved at the same time as the uniformity of the spot.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TN248

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本文編號：1504583