| 摘要(英) |
The objective of this paper is to improve upon the 50 kHz error encountered by senior Ting-Ju Chen when using dispenser to collect data in a vacuum[1]. The ultimate goal is to measure the hyperfine structure and absolute frequency of the 6D5/2 state in the future.
Our system consists of two laser systems, referred to as the master laser and the slave laser. The master laser frequency is locked to the 6S1/2 F = 3, 4 → 6D3/2 transition line. The slave laser frequency is controlled via an offset frequency lock technique to obtain the Doppler-free two photon transition line in a vacuum. We improved upon the vacuum chamber designed by senior Chi-Hsiang Chu, using an ampoule to provide Cs in a vacuum and measuring the absolute frequency and hyperfine structure of the 6D3/2 state[2].
Our new vacuum design generates a higher particle concentration than the Cs vapor produced by the dispenser[1]. The signal strength is comparable to that obtained with a standard Pyrex cell, with a higher signal to-noise ratio. In the region where Cs interacts with the laser, we use a Helmholtz coil to mitigate magnetic interference and avoid frequency shifts caused by the Zeeman effect. Power stabilization via an AOM is employed to measure the AC Stark shift.
During the measurement of the collision shift, we found that particle concentration is affected by the pumping rate at the gate valve, impacting the signal strength and linewidth of the spectral lines. Additionally, we discovered that the frequency accuracy of the Rb clock provided by Chunghwa Telecom varies over time, leading to inaccurate absolute frequency measurements. The frequency accuracy of the Rb clock can degrade from 1 ∗ 10−11 to 5 ∗ 10−11 over six weeks, causing a shift of approximately 17 kHz in our system.
Finally, when measuring the frequency intervals of the four energy levels of 6D3/2, we found a significant discrepancy compared to the data measured by Senior Jeng En[3]. Consequently, we measured the data for the transition 6S1/2 F = 3 → 6D3/2 to confirm whether 6S1/2 F = 3, 4 conform to clock frequency, recalculated the value of the hyperfine coupling constant, and compared it with past values. |
| 參考文獻 |
[1] 陳亭儒, “銫原子6s1/2-6d3/2 超精細躍遷絕對頻率與超精細結構,” 中央大學物理系碩士論文(2017).
[2] 祝麒翔, “銣原子光鐘絕對頻率之量測absolute frequency of rubidium clock,” 中央大學物理系碩士論文(2020).
[3] H.-H. Y. T.-W. L. Y.-F. H. Y.-C. C. M.-S. C. TING-JU CHEN, JENG-EN CHEN and W.-Y. CHENG, “Absolute frequency of cesium 6s1/2–6d3/2 hyperfine transition with a precision to nuclear magnetic octupole interaction,” Optics Letters, vol. 43, no. 9, (2018).
[4] E. S. P. N. Ph. Georgiades and H. J. Kimble, “Five ways to the nonresonant dynamic stark effect,” American Journal of Physics, vol. 79, no. 477, (2011).
[5] W. Demtröder, “Laser spectroscopy: Basic concepts and instrumentation,” 4th ed.(2008).
[6] L. Kelvin and P. G. Tait, “Elements of natural philosophy,” (1890).
[7] J. C. Hafele, “Performance and results of portable clocks in aircraft,” defense technical information center, vol. ADA489971, p. 29, (1971).
[8] 吳淑蓉, “銫原子穩頻822 奈米二級光鐘吳淑蓉cesium-stabilized 822-nm secondary optical clock,” 中央大學物理系碩士論文(2015).
[9] V. G.-T. M. F. S. A. D.-L. H. Jason E. Stalnaker, Vela Mbele and C. E. Tanner,“Femtosecond frequency comb measurement of absolute frequencies and hyperfine coupling constants in cesium vapor,” PHYSICAL REVIEW, vol. 81, no. 4, (2010).
[10] G. Grynberg and B. Cagnac, “Doppler-free multiphotonic spectroscopy,” Reports on Progress in Physics, vol. 40, no. 7, (1977).
[11] 陳正恩, “銫原子蘭道g 值之量測,” 中央大學物理系碩士論文(2020).
[12] A. D. Vladislav Gerginov and C. E. Tanner, “Observation of the nuclear magnetic octupole moment of 133cs,” Phys. Rev. Lett, vol. 91, no. 7, (2003).
[13] E. S. P. N. Ph. Georgiades and H. J. Kimble, “Two-photon spectroscopy of the 6s1/2-6d5/2 transition of trapped atomic cesium,” Opt. Lett, vol. 19, no. 18, (1994).
[14] P. J. Mohr and B. N. Taylor, “Codata recommended values of the fundamental physical constants: 1998,” Rev. Mod. Phys. 72, 351, (2000).
[15] M. I. E. Arimondo and P. Violino, “Experimental determinations of the hyperfine structure in the alkali atoms,” Rev. Mod. Phys. 49, 31, (1977).
[16] H.M.FOLEY, “The pressure broademna of spectral lines,” PHYSICAL REVIEW, vol. 69, no. 11 &12, (1946).
[17] D. A. Steck, “Cesium d line data,” Theoretical Division, (1998).
[18] N. A. M. A. Kortyna and T. Bragdon, “Measurement of the 6d 2dj hyperfine structure of cesium using resonant two-photon sub-doppler spectroscopy,” PHYSICAL REVIEW A. 74, 022503, (2006).
[19] T. F. M. S. Tomoaki Ohtsuka, Nobuo Nishimiya, “Doppler-free two-photon spectroscopy of 6s1/2 -6d3/2,5/2transition in cesium,” Physical Society of Japan, vol. 74, no. 9, (2005). |
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