摘要A novel and simple method to realize polarization gradient cooling (PGC) is reported. The stabilizing, shifting and rapid tuning of the frequency of the external cavity diode laser is realized by using the Zeeman-effect-assisted Doppler-free saturated absorption technique. Based on this convenient technique, 87Rb cold atoms are captured from room-temperature background vapor in the magneto-optical trap (MOT). Meanwhile, the steady-state number, the density and the lifetime of atoms in the MOT are measured. Subsequently, a frequency-fast-varying circuit is designed to realize PGC, which is demonstrated effectively and reliably in experiments. The temperature of the cold atom cloud is measured by two different methods, which coincide with each other.
Abstract:A novel and simple method to realize polarization gradient cooling (PGC) is reported. The stabilizing, shifting and rapid tuning of the frequency of the external cavity diode laser is realized by using the Zeeman-effect-assisted Doppler-free saturated absorption technique. Based on this convenient technique, 87Rb cold atoms are captured from room-temperature background vapor in the magneto-optical trap (MOT). Meanwhile, the steady-state number, the density and the lifetime of atoms in the MOT are measured. Subsequently, a frequency-fast-varying circuit is designed to realize PGC, which is demonstrated effectively and reliably in experiments. The temperature of the cold atom cloud is measured by two different methods, which coincide with each other.
[1] Metcalf H J and vander Straten P 2003 J. Opt. Soc.Am. B 20 887 [2] Tiwari V B, Singh S, Rawat H S and Mehendale S C 2008 Phys. Rev. A 78 063421 [3] De S, Dammalapati U, Jungmann K and Willmann L 2009 Phys. Rev. A 79 041402 [4] Zhang W Z, Wang X C, Cheng H D, Xiao L, Liu L and Wang Y Z2009 Chin. Phys. Lett. 26 083703 [5] Deng J L, Hu Z F, He H J and Wang Y Z 2006 Chin.Phys. Lett. 23 1745 [6] Folman R, Kr\"{uger P, Cassettari D, Hessmo B, Maier Tand Schmiedmayer J 2000 Phys. Rev. Lett. 84 4749 [7] Li X L, Ke M, Tang J Y and Zhou S Y 2005 Chin. Phys.Lett. 22 2526 [8] Oberthaler M K and Pfau T 2003 J. Phys. Condens.Matter 15 R233 [9] Weiss D S, Young B C and Chu S 1994 Appl. Phys. B 59 217 [10] Chu S, Bjorkholm J E and Cable A 1986 Phys. Rev.Lett. 57 314 [11] Balykin V I, Minogin V G and Letokhov V S 2000 Rep.Prog. Phys. 63 1429 [12] Ye J, Swartz S, Jungner P and Hall J L 1996 Opt.Lett. 21 1280 [13] Han S L, Cheng B, Zhang J F, Xu Y F, Wang Z Y and Lin Q2009 Chin. Phys. Lett. 26 063201 [14] Raab E L, Prentiss M, Cable A, Chu S and Pritchard D E1987 Phys. Rev. Lett. 59 2631 [15]Monroe C, Robinson H and Wieman C 1991 Opt. Lett. 16 50 [16] Monroe C, Swann W, Robinson H and Wieman C 1999 Phys. Rev. Lett. 65 1571 [17] Permyakova O I, Yakovlev A V and Chapovsky P L 2008 Quantum Electron. 38 884 [18] Dalibard J and Cohen-Tannoudji C 1989 J. Opt. Soc.Am. B 6 2023 [19] Steane A M and Foot C J 1991 Europhys. Lett. 14 231 [20] Donley E A, Heavner T P, Levi F, Tataw M O and Jefferts SR 2005 Rev. Sci. Instrum. 76 063112 [21] Wang Y Q 2007 Laser Cooling and Trapping of Atoms(Peking: Peking University) p 178 (in Chinese) [22] Pradhan S and Jagatap B N 2008 Rev. Sci. Instrum. 79 013101 [23] Brzozowski T M, Maczynska M, Zawada M, Zachorowski J andGawlik W 2002 J. Opt. B: Quantum Semiclass. Opt. 4 62