Wienold M, Alam T, Schrottke L, Grahn H T, Hübers H-W
Opt Express. 2018 Mar 19;26(6):6692-6699. doi: 10.1364/OE.26.006692.
We report on the Doppler-free saturation spectroscopy of a molecular transition at 3.3 THz based on a quantum-cascade laser and an absorption cell in a collinear pump-probe configuration. A Lamb dip with a sub-Doppler linewidth of 170 kHz is observed for a rotational transition of HDO. We found that a certain level of external optical feedback is tolerable as long as the free spectral range of the external cavity is large compared to the width of the absorption line.
我们报道了基于量子级联激光器和处于共线泵浦-探测配置的吸收池，对3.3太赫兹处分子跃迁进行的无多普勒饱和光谱研究。对于HDO的转动跃迁，观测到了具有170千赫兹亚多普勒线宽的兰姆凹陷。我们发现，只要外腔的自由光谱范围比吸收线宽度大，一定程度的外部光反馈是可以容忍的。
