1. TB06 TB06 PRECISION FREQUENCY MEASUREMENT OF N 2 O TRANSITIONS NEAR 4.5  m AND ABOVE 150  m WEI-JO TING, CHUN-HUNG CHANG, SHIH-EN CHEN, HSUAN CHEN CHEN, JOW- TSONG SHY, BRIAN DROUIN, ADAM DALY Jet Propulsion Laboratory, California Institute of Technology, Department of Physics, National Tsing Hua University, Institute of Photonics Technologies, Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University 6/17/2014TB061

2. Background and Motivation 66 th molecular spectroscopy symposium – TA10 - HIGH PRECISION MID-IR SPECTROSCOPY OF N 2 O NEAR 4.5 μm Similar to CO 2, N 2 O is one of the important greenhouse gases. No extensive heterodyne frequency measurements of the line center. New and refined molecular constants are of great importance to atmospheric chemistry, meteorology, and astrophysics. Drouin, B. J., F.W. Maiwald, "Extended THz measurements of nitrous oxide, N 2 O," Journal of Molecular Spectroscopy, 236 (2): 260-262, 2006. 60 th molecular spectroscopy symposium – WI08 - Applications of Molecular Spectroscopy Using Cascaded Frequency Multiplication Work was directed at characterizing multipliers, not necessarily precision measurements 6/17/2014TB062

3. Partial energy diagram of N 2 O 00 0 0 00 0 1 02 0 0 01 1 0 10 0 0 01 1 1 2223 cm -1 589 cm -1 2789 cm -1 2209 cm -1 1285 cm -1 1168 cm -1 939 cm -1 1056 cm -1 Green : Laser transitions that have been measured by Whitford et al.(1975) Blue : Suggested by Dr. A. G. Maki. Red: Can be derived from Blue and Green transitions. 6/17/2014TB063

4. mW PPLN Difference Frequency Generation Source Experimental Set-up Third derivative signal of the R(10) saturation dip. Here, the scan rate is 2.0 MHz/s and lock-in time constant is 30 ms. 44 transitions J = 1 – 100 P- and R- branches 6/17/2014TB064

5. New and refined molecular constants are of great importance to atmospheric chemistry, meteorology, and astrophysics. 00 0 0 00 0 1 02 0,2 0 01 1 0 10 0 0 01 1 1 2223 cm -1 589 cm -1 2789 cm -1 2209 cm -1 1285 cm -1 1168 cm -1 939 cm -1 1056 cm -1 Combined Precision Datasets require sophisticated analysis 6/17/2014TB065

6. SPFIT can do it N2O gs and vibs only Thu Feb 20 09:00:15 2014 58 860 1111 1 0.0000E+000 1.5000E+010 1.0000E+000 1.0000000000 's' -1 6 -2 2 0 2 1 1 -1 99 0 -1 0 0 0 0 2 1 1 -1 99 /GS -1 1 0 0 0 2 1 1 -1 99 /0001 -1 2 1 1 0 2 1 1 -1 99 /0110 -1 3 0 0 0 2 1 1 -1 99 /1000 -1 4 0 0 0 2 1 1 -1 99 /0200 -1 5 2 2 0 2 1 1 0 99 /0220 11 6.666654998427864E+007 1.00000000E+037 22 1.766339494777190E+007 1.00000000E+030 33 3.812427877840588E+007 1.00000000E+037 44 3.541588237732284E+007 1.00000000E+037 55 3.550941357195968E+007 1.00000000E+037 100 1.256163434389935E+004 1.00000000E+037 111 1.245816128474397E+004 1.00000000E+037 122 1.257849923157786E+004 1.00000000E+037 -1022 -1.257849923157786E+004 1.00000000E-037 133 1.250391779931895E+004 1.00000000E+037 144 1.259395199651880E+004 1.00000000E+037 155 1.259489331159831E+004 1.00000000E+037 -1055 -5.037957324639328E+004 1.00000000E-037 … 40022 -1.187183717086132E+001 1.00000000E+037 40122 1.543894523928355E-005 1.00000000E+037 40222 -9.191963478521138E-011 1.00000000E+037 40045 -1.722464138604733E+001 1.00000000E+037 40145 1.403374965327052E-005 1.00000000E+037 40245 -4.350971105355596E-010 1.00000000E+030 143 8.071549516948119E+000 1.00000000E+030 43 -1.109000000000000E+006 1.00000000E-030 /WF 6/17/2014TB066

7. Precision IR vs. THz Addition of IR saturation spectra to analyses revealed errors in ground state measurements of Drouin & Maiwald 2005 Improvements to THz coverage and gas cells suggested we try harder TransitionObserved frequency (MHz) a f obs -f cal ( ｋ Hz) f obs -f HITRAN (MHz) P(90)63593300.821(75) 348.541 P(85)63806246.166(50)-95.307 P(80)64014332.292(25)-142.490 P(75)64217537.679(25)-52.553 …. 6/17/2014TB067

8. The Frequency Multiplication Submillimeter Spectrometer AMC-10 Anritsu SR830 HP FG AM/FM/TM sync diode or Si gas pre-amp vacuum pump sample sweep synthesizer mm-wave module MMIC amps submm multipliers waveguide feedhorns sample cell detector waveform generator lock-in-amplifier PC GPIB modulation AMC - 12AMC-10D170D190D210X3 WR1.9x5D210X3X2X3 50-7575-110160-180180-200200-220220-270270-330400-550550-700700-800GHz 1.7-2.52.5-3.75.3-66-6.76.7-7.37.3-99-1113.3-18.318.3-23.323.3-26cm -1 WR1.2x5X2X2X2X3X3X2X2X3X3X3X2D170 X9D190 X9D210 X9X3X3X3 750-850850-930950-10601060-12201290-14001400-16001600-18001800-20502475-2775GHz 25-28.328.3-3131.7-35.335-3-40.743-46.746.7-53.353.3-6060-68.382.5-92.5cm -1 HPWR3.4 ZBDWR1.9 ZBDWR0.8 ZBDQODInSbSiPM < 100220-330400-600900-140090 – 200090-800400-100001-3000GHz < 3.37.3-1113.3-2030-46.73-67.73-27.713.3-3330.1-100cm -1 6/17/2014TB068

9. Lamb Dips with THz sources Pearson J., B. Drouin, A. Maestrini, I. Mehdi, J. Ward, R. Lin, S. Yu, J. Gill, B. Thomas, C. Lee, G. Chattopadhyay, E. Schlecht, F. Maiwald, P. Goldsmith, P. Siegel "Demonstration of a room temperature 2.48-2.75 THz coherent spectroscopy source", Review of Scientific Instruments 82(9), 093105, 2011. Routine for strong lines < 1 THz, Schottky detectors below 0.7 THz, Si bolometers above 0.7 THz. Lamb-Dip ‘machine’ built by T. Crawford 6/17/2014TB069

10. New THz Measurements 175 new pure rotational transitions 33 sub-Doppler Second harmonic detection of saturated absorption dip for the J = 12 – 11 rotational transition in the 02 0 0 state. The pressure was 0.1 Pa, the modulation depth was 18 kHz, resulting in a linewidth of 22 kHz and a frequency measurement uncertainty of 1 kHz. J’l’v’JlvFrequency (MHz) Uncertaint y (MHz) 803703200133.25000.0300 800700200975.33310.0010 81272201055.26080.0030 804704201406.95700.0200 82712201435.09190.0030 8-25725201509.96000.0300 8257-25201513.56500.0300 … 6/17/2014TB0610

11. New & Improved Model 00 0 010 0 001 1 000 0 102 0 002 ±2 0 b EnEn -66666549.9843(32)17663394.948(33)38124278.7784(37)35415882.3773(73)35509413.572(63) BnBn 12561.6343439(127)12458.1612847(156) 12578.4992316(167) 12503.9178(97) a 12593.9520(97) a 12594.893312(35) D n / kHz5.2795480(163)5.2609739(188)5.3617941(248)5.321111(260)5.45696(33)5.444018(103) H n / mHz-0.4661( 83)-0.3499(91)-0.3448(140)-0.4951(165) -8.37(287) -0.306(55) L n / nHz-9.25(155)-9.57(162)-15.24(199)-13.4(75) M v / pHz0.290(95)fffff q n / MHz -11.8718372(147) -17.22464(42) 0.014034(265) -0.435(40) q nJ / kHz 0.0154389(144) q nJJ / mHz -0.09192(242) W F / GHz 1109 b 8.0715(119) W FJ / kHz Datasetavg. (MHz)s.d. (MHz) σ red N This Work-THz-0.00330.03260.845182 This work-IR 0.00040.01251.04944 Burrus & Gordy [5]-0.06100.07620.5064 Pearson et al. [6]-0.01170.05930.63729 Lafferty & Ride [7]0.00400.05020.7644 Andreev et al. [8]0.00390.01250.82955 Morino et al. [9]-0.04120.04212.1075 Drouin &Maiwald [10]0.00180.05780.76970 Morino et al. [11]0.00550.03480.43331 Lemaire et al. [12]-0.00580.01200.1203 Tachikawa et al. [15]0.00080.01011.093129 Hornemann [16]0.1000.80421.148301 Stateavg. (MHz)s.d. (MHz) σ red N g.s0.00280.03251.11479 00 0 10.02500.08280.9656 01 1 0-0.00400.03290.718125 10 0 00.00170.03300.81630 02 0 0-0.00180.05220.79849 02 ±2 0-0.00740.04460.72197 10 0 0-00 0 0 0.00040.01251.04944 01 1 0-00 0 00.11530.27930.79554 02 0 0-01 1 00.09640.84561.175114 02 ±2 0-01 1 00.09580.90501.242133 10 0 0-00 0 10.00100.00781.14191 10 0 0-02 0 00.00010.01420.96738 6/17/2014TB0611

12. Acknowledgements National Science Council, Taiwan Ministry of Education, Taiwan NASA ACLAB JPL SWAT JPL TEFIM 6/17/2014TB0612 © 2014 California Institute of Technology. Government sponsorship acknowledged.