1 中国科学院大连化学物理研究所化学激光重点实验室, 辽宁 大连 116023
2 中国科学院重大科技任务局, 北京 100864
3 大连理工大学物理学院, 辽宁 大连 116023
研究钠氩(Na-Ar)混合物电离后产生的原子发射光谱的时间分辨特性。氩763.5 nm光谱强度随时间演变出现2个峰,第1个峰的衰减时间为(33.3±2.3) ns,激发态钠通过碰撞传能[(时间常数为(15.2±0.8) ns]将氩激发到2p6能级,再由该能级的粒子快速辐射形成第1个峰;第2个峰由氩离子与电子复合产生,其衰减过程包括快过程[(0.24±0.03) μs]和慢过程[(3.98±1.03) μs]。利用电子浓度随时间的演变关系分析了复合过程对衰减时间的影响机理,获得了电子浓度、电子温度随时间的演变关系。利用时间分辨光谱解释了钠双线辐射加宽差异的假象,其成因是Stark加宽后的氩588.9 nm谱线叠加在钠D2线上以及钠双线的自吸收。复合后,激发态氩原子的能级间隔较小,经过级联弛豫后,2p6能级粒子数的积累时间比钠3P能级更短,氩原子发射谱线的持续时间明显短于钠原子。
激光器 准分子激光 碱金属蒸气 Stark加宽 荧光寿命 自吸收 时间分辨原子发射光谱
Author Affiliations
Abstract
1 Key Laboratory of Chemical Lasers, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
Sodium-ethane excimer pairs are studied and proved to be a great choice of excimer pumped sodium laser (XPNaL) gain media. The lifetime of the sodium D2 line is studied in a sodium-ethane excimer system excited by a 553 nm laser, and the observed phenomenon of lifetime lengthening is discussed. Amplified spontaneous emission (ASE) of the sodium D2 line is successfully obtained, and its time-resolved and spectroscopic characteristics are studied experimentally. According to the intensity of the ASE signal under different sodium vapor atom densities, the sodium D2 line gain feature of sodium-ethane excimer pairs excited by the 553 nm laser is concluded.
140.1340 Atomic gas lasers 140.2180 Excimer lasers Chinese Optics Letters
2017, 15(11): 111401
1 中国科学院大连化学物理研究所化学激光重点实验室, 辽宁 大连 116023
2 中国科学院大学, 北京 100049
准分子宽带抽运钠金属激光器具有实现钠信标光源的潜质, 该激光器在运转过程中需要借助准分子将钠原子由基态转换为激发态, 因此有必要对由准分子解离产生的钠原子激发态荧光寿命开展实验研究。采用不同波长的蓝翼抽运光对不同温度的钠乙烷准分子体系进行激发, 分别测量钠D1线和钠D2线的荧光寿命。结果表明, 32P3/2与32P1/2能级的荧光寿命明显长于其自然寿命, 且激发波长越长, 荧光寿命延长得越明显。辐射捕获效应是导致荧光寿命延长的另一个因素。随着泵浦单光子能量下降, 钠乙烷准分子被激发到A2Π3/2态的概率变大, 能够长时间产生激发态钠原子, 这也会使荧光寿命延长。与钠D1线相比, 钠乙烷准分子体系钠D2线的放大自发辐射信号的可放大性更好。更好的可放大性以及较长的荧光寿命使得钠D2线激光更易于实现。
激光器 受激准分子激光器 碱金属蒸气 荧光寿命 辐射俘获 放大自发辐射
Author Affiliations
Abstract
1 School of Science, Changchun University of Science and Technology, Changchun 130022, China
2 Key Laboratory of Chemical Lasers, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian 116023, China
Pulsed collimated blue light at 420.3 nm is generated in hot Rb vapor by upconverting the 778.10 nm pumping beam through four wave mixing process. The energy conversion efficiency exceeds 1% when a 45 cm-long, 170°C heated Rb cell is used. The influence of cell temperature, wavelength, and energy of a pumping laser are fully examined. The efficiency of the photon conversion is found to be more sensitive to the blue detuning of the pump light and less sensitive to the red detuning of the pump light. This phenomenon can be explained by stimulated hyper-Raman scattering involved in the four-wave mixing process.
190.4380 Nonlinear optics, four-wave mixing 190.4180 Multiphoton processes 190.7220 Upconversion 300.6210 Spectroscopy, atomic Chinese Optics Letters
2015, 13(12): 121903
