School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47906, USA.
Opt Lett. 2012 Sep 1;37(17):3564-6. doi: 10.1364/OL.37.003564.
We have developed a high-spectral-resolution laser system for two-photon pump, polarization spectroscopy probe (TPP-PSP) measurements of atomic hydrogen in flames. In the TPP-PSP technique, a 243-nm laser beam excites the two-photon 1S-2S transition, and excited n=2 atoms are then detected by polarization spectroscopy of the n=2 to n=3 transition using 656-nm laser radiation. The single-frequency-mode 243 and 656-nm beams are produced using injection-seeded optical parametric generators coupled with pulsed dye amplifiers. The use of single-mode lasers allows accurate measurement of signal line shapes and intensities even with significant pulse-to-pulse fluctuations in pulse energies. Use of single-mode lasers and introduction of a scheme to select nearly constant laser energies enable repeatable extraction of important spectral features in atomic hydrogen transitions.
我们开发了一种用于双光子泵浦、偏振光谱探测（TPP-PSP）测量火焰中原子氢的高光谱分辨率激光系统。在 TPP-PSP 技术中，243nm 激光束激发双光子 1S-2S 跃迁，然后通过使用 656nm 激光辐射探测 n=2 到 n=3 跃迁的偏振光谱来检测激发的 n=2 原子。单频模式 243nm 和 656nm 光束是通过注入种子的光学参量发生器与脉冲染料放大器耦合产生的。使用单模激光器，即使在脉冲能量的显著脉冲到脉冲波动下，也可以准确测量信号线形状和强度。使用单模激光器并引入一种选择几乎恒定激光能量的方案，可实现原子氢跃迁中重要光谱特征的可重复提取。
