Nd:YVO4/YVO4晶体的热键合及其激光性质的研究

为改善高功率激光器激光工作物质的热效应,本文采用热键合的方法研制了Nd:YVO4/YVO4复合晶体,键合晶体的波前干涉P-V值为0.082λ(λ=0.6328μm),键合面对波前的影响很小.它在LD端面连续泵浦条件下,从泵浦光到基频光的转换效率可达60;, 特别当泵浦功率比较大时,键合晶体的输出功率比单块晶体有较大的提高.     

搅拌子固相吸附-热脱附-气相色谱/质谱/质谱法快速测定空气中多环芳烃

利用聚二甲基硅氧烷(PDMS)涂层的搅拌子作为大气被动采样器,建立了搅拌子固相吸附-热脱附-气相色谱/质谱/质谱联用法(SBSE-TD-GC/MS/MS)快速测定室内空气中多环芳烃的方法。在搅拌子表面涂渍标准样品,待溶剂挥发后放于脱附管内,在多反应监测模式(MRM)下,对多环芳烃子离子、碰撞能量、热脱附参数(脱附温度300℃,冷阱捕集温度-60℃和脱附时间6 min)等条件进行了优化,并建立标准曲线;以12种氘代同位素PAHs为内标,建立了多窗口下16种美国环保署优先检测多环芳烃的分析方法,方法回收率在45.1%~109%之间,检出限为0.020~0.054 ng。利用本方法对模拟燃煤前后室内大气中悬挂搅拌子中的多环芳烃进行了被动吸附与检测,燃煤前后室内大气样品中16种多环芳烃含量分别为4.24~5.32 ng和172~200 ng。     

Study on optical characteristics of Nd:YVO_4/YVO_4 composite crystal laser

Thermal effect in crystals is the main obstacle blocking diode-pumped solid state laser to get high and stable output, power. Diffusion bonding crystal has been demonstrated to be an effective method to relieve the thermal lensing theoretically based on the numerical heat analysis to the end-pumped anisotropic laser crystal. The temperature distributions in Nd:YV04/YVO4 composite crystal and conventional crystal were analyzed and compared. The end-pumped Nd:YVO4/YVO4 composite crystal laser was designed and set up with 2-cavity. The maximum output powers of 9.87 W at 1064 nm and 6.14 W at 532 nm were obtained at the incident purnp power of 16.5 W. The highest optical-optical conversion efficiencies were up to 59.8% at 1064 nm and 37.2% at 532 nm respectively.