Cavity Ring-down Spectroscopy Of Hydrogen In The 784-852 nm Region And Corresponding Line Shape Implementation Into HITRAN Yan Tan (a,b), Jin Wang (a), Cun-Feng Cheng (a), An-Wen Liu (a), Shui-Ming Hu (a), P. Wcislo (b,c), R.V Kochanov (b,d), I.E. Gordon (b), L.S. Rothman (b) (a)Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China; (b) Atomic and Molecular Physics Division , Harvard-Smithsonian Center for Astrophysics, USA; (c) Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Poland;(d)Laboratory of Quantum Mechanics of Molecules and Radiative Processes, Tomsk State University, Russia University of Science and Technology of China

S Q O Cavity Ring-down Spectroscopy Of Hydrogen J Most abundant molecule in universe Most fundamental neutral molecule Unique molecule – line shape study Homonuclear diatomic molecule p o 1 2 3 J S Q O 784-852nm n=3-0

CW Cavity Ring-down System Cavity Ring-down Spectroscopy Of Hydrogen CW Cavity Ring-down System OFF time Iout ON Ring Down ! I =I0 exp(-t/τ) In Out OFF Laser Ring-down Cavity Laser Pump AOM Trigger ULE Etalon DAQ PD PZT

Cavity Ring-down Spectroscopy Of Hydrogen Ultrahigh sensitivity Equivalent absorption path length Leff ≈ L/(1-R), Leff ~102 km High frequency accuracy Calibrated with atomic lines, <2MHz In Out L R

Good signal-to-noise ratio for accuracy value Cavity Ring-down Spectroscopy Of Hydrogen Good signal-to-noise ratio for accuracy value V=30, J=75 Line intensity: 9.2×10-31 cm/molecule at 296 K H2, Q(1) Galatry:rms~2.6×10-11 cm-1

Cavity Ring-down Spectroscopy Of Hydrogen Positions and intensities for the transitions of (3 - 0) H2 band measured by CRDS

Cavity Ring-down Spectroscopy Of Hydrogen Line position and intensity determination : 3X10-4cm-1 : -1% Calculation from Pachucki et al., Phys. Rev. A 83, 042510 

Corresponding Line Shape Implementation Into HITRAN Experimental data analysis implementation OF-CEAS high-pressure Raman spectra (1-0) CRDS spectra [in Grenoble] (2-0) Our work : CRDS spectra (3-0) HITRAN Application Programming Interface (HAPI) New HITRAN online http://hitran.org/ non-Voigt profile HTP (Hartmann-Tran profile) quadratic speed dependence + hard-collisions model P. Wcisło, et al. , J Quant Spectrosc Radiat Transf, 177, 75-91(2016)

Corresponding Line Shape Implementation Into HITRAN 3-0 S(1) line

Corresponding Line Shape Implementation Into HITRAN The results of the OF-CEAS and the CRDS spectra analysis for the (1-0), (2-0) and (3-0) bands:

Corresponding Line Shape Implementation Into HITRAN From HITRANonline: http://hitran.org/ New Output Format Parameter Units C|Fortran Format

Corresponding Line Shape Implementation Into HITRAN Profile Function name Parameters Voigt PROFILE_VOIGT GD, G0, D0 Speed-dependent Voigt PROFILE_SDVOIGT GD, G0, G2, D0, D2, Rautian PROFILE_RAUTIAN GD, G0, D0, nVC Speed-dependent Rautian PROFILE_SDRAUTIAN GD, G0, G2, D0, D2, nVC Hartmann-Tran PROFILE_HT GD, G0, G2, D0, D2, nVC, h Sample spectra by using HAPI to simulate the absorption coefficient of H2 1-0 band Presentation by Roman, “ HITRAN APPLICATION PROGRAMMING INTERFACE (HAPI): EXTENDING HITRAN CAPABILITIES” Tuesday, TG12 : P1951 R.V. Kochanov, et al. , J Quant Spectrosc Radiat Transf, 177, 15-30(2016)

Summary and Outlook For experiments: For HITRANonline Have done: High precision measurement of ro-vibrational transitions of H2 These spectroscopy data along with others have been reanalyzed as a test for non-Voigt profile to HITRAN database For experiments: Calibration with combs : toward sub-ppb (0.1MHz) Thermo-stabilized (1mK) sample cell : toward a determination of kB For HITRANonline Successfully tested the Hartman-Tran profile : more measurements for other molecules Keep on updating the database : http://hitran.org/ Introducing line-mixing effect: CH4

Acknowledgements Thanks for the help of our former group members ( Shui-Ming Hu, An-Wen Liu, Jin Wang and many others…). Also thanks for the help of our HITRAN group members (Laurence Rothman, Iouli Gordon, Roman Kochanov …). University of Science and Technology of China HITRANonline: http://hitran.org/

Thanks for your attention! University of Science and Technology of China