Bair C H, Allario F
Appl Opt. 1977 Jan 1;16(1):97-100. doi: 10.1364/AO.16.000097.
Absorption coefficients in the fundamental P-branch of HCl at several DF laser transitions from 2439.02 cm(-1) to 2862.87 cm(-1) have been measured experimentally. The 2-1 P(3) DF laser transition has been shown to overlap the P(6) HCl(37) absorption line within the halfwidth of an atmospherically broadened line. The absorption coefficient k was measured to be 5.64 +/- 0.28 (atm-cm)cm(-1) for a 0.27% mixture of HCl in N(2) at a total pressure of 760 Torr. A theoretical and experimental comparison of the pressure dependence of k showed that the 2-1 P(3) DF transition lies 1.32 +/- 0.15 GHz from the center of the P(6) HCl absorption line. This line separation is in good agreement with published positions for this DF laser transition and the HCl absorption line. At least four other DF laser transitions in the spectral interval measured are reported showing measurable absorption (>/=10%) for a 10.2% mixture of HCl in N(2) across a 1-m pathlength. Applications of these results to differential absorption lidar (DIAL) and to heterodyne detection are also discussed.
已通过实验测量了HCl在从2439.02厘米⁻¹至2862.87厘米⁻¹的几个DF激光跃迁的基频P支中的吸收系数。已表明2-1 P(3) DF激光跃迁在大气加宽线的半高宽内与P(6) HCl(37)吸收线重叠。在总压力为760托的条件下，对于N₂中HCl含量为0.27%的混合物，测得吸收系数k为5.64±0.28（大气压·厘米）厘米⁻¹。k对压力依赖性的理论与实验比较表明，2-1 P(3) DF跃迁与P(6) HCl吸收线中心的距离为1.32±0.15吉赫兹。该谱线间距与已发表的该DF激光跃迁和HCl吸收线的位置高度吻合。报告了在所测量的光谱区间内至少还有其他四个DF激光跃迁，显示对于N₂中HCl含量为10.2%的混合物，在1米光程上有可测量的吸收（≥10%）。还讨论了这些结果在差分吸收激光雷达（DIAL）和外差检测中的应用。
