Precision saturated absorption spectroscopy of H3+

Guan, Yu-chan

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https://hdl.handle.net/2142/91426 Copy

Description

Title

Precision saturated absorption spectroscopy of H3+

Author(s)

Guan, Yu-chan

Contributor(s)

• Shy, Jow-Tsong
• Peng, Jin-Long
• Chang, Yung-Hsiang
• Liao, Yi-Chieh

Issue Date

2016-06-20

Keyword(s)

Ions

Abstract

In our previous work on the Lamb dips of the \nub{2} fundamental band of H$_{3}$$^{+}$, the saturated absorption spectrum was obtained by the third-derivative spectroscopy using frequency modulation [1]. However, the frequency modulation also causes error in absolute frequency determination. To solve this problem, we have built an offset-locking system to lock the OPO pump frequency to an iodine-stabilized Nd:YAG laser. With this modification, we are able to scan the OPO idler frequency precisely and obtain the profile of the Lamb dips. Double modulation (amplitude modulation of the idler power and concentration modulation of the ion) is employed to subtract the interference fringes of the signal and increase the signal-to-noise ratio effectively. To Determine the absolute frequency of the idler wave, the pump wave is offset locked on the R(56) 32-0 a$_{10}$ hyperfine component of $^{127}$I$_{2}$, and the signal wave is locked on a GPS disciplined fiber optical frequency comb (OFC). All references and lock systems have absolute frequency accuracy better than 10 kHz. Here, we demonstrate its performance by measuring one transition of methane and sixteen transitions of H$_{3}$$^{+}$. This instrument could pave the way for the high-resolution spectroscopy of a variety of molecular ions. [1] H.-C. Chen, C.-Y. Hsiao, J.-L. Peng, T. Amano, and J.-T. Shy, Phys. Rev. Lett. 109, 263002 (2012).

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

En

Permalink

http://hdl.handle.net/2142/91426

Copyright and License Information

Copyright 2016 by the authors

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