【摘要】：本碩士論文包含兩部分的工作,其中第一部分是激光誘導擊穿光譜(LIBS)技術在液體樣品方面的技術發(fā)展和應用進展綜述,另一部分是雙色激光與氣體作用產生太赫茲輻射的理論模擬研究。LIBS技術經過50年的發(fā)展已經成為進行元素檢測的重要工具,被廣泛應用于固態(tài)、液態(tài)、氣態(tài)樣本中。與LIBS技術應用于固態(tài)樣本相比,由于液體樣本中LIBS光譜強度較弱,所以分析效果不佳。但是傳統(tǒng)的液體樣本元素的檢測方法僅局限于實驗室研究,而LIBS可遠程、實時、在線進行元素分析,具有極大的吸引力。故眾多研究者致力于液體LIBS信號的優(yōu)化研究。本文重點介紹了液體LIBS的特性、常用的取樣方法、定標方法,以及在工業(yè)、日常生活、環(huán)境檢測、生物醫(yī)藥等諸多方面的重要應用。第二部分是關于雙色激光與氣體作用產生太赫茲輻射的理論模擬,主要是探討這種條件下太赫茲輻射產生的物理機制。太赫茲(THz)輻射通常是指頻率介于0.1-10THz的電磁輻射,在電磁波譜中處于高頻微波和紅外光之間。目前強激光與氣體靶作用是產生高功率太赫茲輻射的一個重要途徑。本文利用光電離電流模型研究了800nm激光和它的半頻光1600nm激光與氣體作用產生強太赫茲輻射的過程。計算表明:(1)不同的氣體種類、雙色激光相位差、激光的振幅均會影響離化電流的大小,可以通過各種參數(shù)對太赫茲振幅強度的影響進行優(yōu)化。(2)通過改變雙色激光偏振方向的夾角,發(fā)現(xiàn)小于72度時產生離化電流的方向開始主要受基頻光偏振方向的影響,大于72度時主要受半頻光的偏振方向影響。
[Abstract]:This thesis consists of two parts. The first part is a review of the development and application of laser-induced breakdown spectroscopy (LIBS) in liquid samples. The other part is the theoretical simulation of terahertz radiation produced by two-color laser and gas. After 50 years of development, LIBS technology has become an important tool for element detection, and has been widely used in solid, liquid and gaseous samples. Compared with the application of LIBS technique in solid samples, the analysis effect is not good because of the weak spectral intensity of LIBS in liquid samples. However, the traditional detection methods of liquid sample elements are limited to laboratory research, and LIBS can be used for element analysis remotely, in real time and online, so it has great attraction. Therefore, many researchers focus on the optimization of liquid LIBS signals. In this paper, the characteristics of liquid LIBS, sampling methods, calibration methods, and important applications in industry, daily life, environmental detection, biomedicine and so on are introduced. The second part is about the theoretical simulation of terahertz radiation produced by the interaction of two-color laser and gas, which mainly discusses the physical mechanism of terahertz radiation under this condition. Terahertz (THz) radiation usually refers to electromagnetic radiation with a frequency between 0.1-10THz and high frequency microwave and infrared light in the electromagnetic spectrum. At present, the interaction between intense laser and gas target is an important way to produce high power terahertz radiation. In this paper, the photoionization current model is used to study the process of strong terahertz radiation produced by 800nm laser and its half-frequency optical 1600nm laser interacting with gas. The results show that: (1) for different gas types, the phase difference of two-color laser, the amplitude of laser will affect the magnitude of ionization current. The influence of various parameters on the amplitude intensity of terahertz can be optimized. (2) by changing the angle of polarization direction of two-color laser, it is found that the direction in which the ionization current is produced when less than 72 degrees is mainly affected by the polarization direction of fundamental frequency light. The polarization direction of the half-frequency light is mainly affected when it is more than 72 degrees.
【學位授予單位】：上海交通大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN24

【相似文獻】

相關期刊論文 前10條

1 周南;周亢;丁圭吉;;關于激光誘導裂析譜專題的歐洲-地中海會議2007(Ⅰ)[J];分析試驗室;2009年08期

2 周南;周亢;丁圭吉;;關于激光誘導裂析譜專題的歐洲-地中海會議2007(Ⅱ)[J];分析試驗室;2009年09期

3 ;激光誘導腦電波[J];激光與光電子學進展;2009年06期

4 周政卓,邱明新,黃賽棠,畢琦秀,顧加O，

本文編號：2139783