CAJ | 학술논문

为了解决单脉冲激光诱导击穿光谱（L IBS ）技术在元素分析时空间分辨本领与分析灵敏度之间的矛盾，本文利用一台双波长输出的Nd∶YAG激光器开展了双波长激光剥离-激光诱导击穿光谱（LA-LIBS）技术的研究。其中532 nm的二倍频激光用于剥离样品；1064 nm的基频激光通过大芯径石英玻璃光纤传输并实现一定的延时后用于击穿被剥离的样品。两束激光采用正交几何配置以实现高空间分辨高灵敏的元素分析。实验研究了1064 nm激光到光纤的耦合、光纤输出后的准直以及再聚焦时的一些关键技术问题。研究并得出了四种不同光纤对激光能量的传输能力。选择利用芯径为800μm ，数值孔径为0.39、长50 m的石英玻璃光纤成功传输了15 mJ的调Q激光脉冲并实现了250 ns的延时。并在此基础上开展了铜合金样品的双波长LA-LIBS分析，实验验证了基于一台Nd∶YAG激光器开展双波长LA-LIBS研究的可行性。该技术只需要一台激光器就可以完成相应的光谱分析，具有系统结构简单，便于小型化等优点，适合对不同样品开展原位的高空间分辨高灵敏的元素显微分析。
위료해결단맥충격광유도격천광보（L IBS ）기술재원소분석시공간분변본령여분석령민도지간적모순，본문이용일태쌍파장수출적Nd∶YAG격광기개전료쌍파장격광박리-격광유도격천광보（LA-LIBS）기술적연구。기중532 nm적이배빈격광용우박리양품；1064 nm적기빈격광통과대심경석영파리광섬전수병실현일정적연시후용우격천피박리적양품。량속격광채용정교궤하배치이실현고공간분변고령민적원소분석。실험연구료1064 nm격광도광섬적우합、광섬수출후적준직이급재취초시적일사관건기술문제。연구병득출료사충불동광섬대격광능량적전수능력。선택이용심경위800μm ，수치공경위0.39、장50 m적석영파리광섬성공전수료15 mJ적조Q격광맥충병실현료250 ns적연시。병재차기출상개전료동합금양품적쌍파장LA-LIBS분석，실험험증료기우일태Nd∶YAG격광기개전쌍파장LA-LIBS연구적가행성。해기술지수요일태격광기취가이완성상응적광보분석，구유계통결구간단，편우소형화등우점，괄합대불동양품개전원위적고공간분변고령민적원소현미분석。
To resolve the contradiction between spatial resolution and analysis sensitivity in single pulse laser-induced breakdown spectroscopy (LIBS) ,a study on dual-wavelength laser-ablation laser-induced breakdown spectroscopy (LA-LIBS) was carried out by using one Nd∶YAG laser which was capable of two laser beam outputs with different wavelengths ,where ,the second harmonic output ,532 nm laser beam ,was used as laser-ablation source ,and the fundamental output ,1 064 nm laser beam ,was delivered with a large core diameter silica fiber to realize nanoseconds time-delay and then used to breakdown the ablated sam-ples .Two laser beams were orthogonally arranged to realize element analysis with high spatial resolution and high sensitivity . Some key techniques on the coupling of 1 064 nm laser beam into fiber ,the collimation of laser at the fiber end and re-focusing of the laser beam were studied .The energy delivery capabilities of four fibers of different types were studied and the maximum val-ues were determined experimentally .A Q-switched laser pulse with 15 mJ pulse energy was successfully delivered by selecting a 50 meter long silica fiber with 800μm core diameter and 0.39 numerical aperture .And 250 ns time-delay was realized .A copper alloy was analyzed by spectra with current established LA-LIBS system and the possibility of realizing dual-wavelength LA-LIBS analysis based on one Nd∶YAG laser was demonstrated experimentally .In this technique ,only one Nd∶YAG laser was re-quired to carry out spectral analysis .It has a few advantages ,such as simple equipment structure ,and being convenient to minia-turize the whole system etc .This dual-wavelength LA-LIBS technique was suitable for in-situ elements microanalysis for differ-ent samples with both high spatial resolution and high sensitivity .