Resonances in the magnetic decoupling curves for the spin relaxation of dense alkali-metal vapors prove that much of the relaxation is due to the spin-axis interaction in triplet dimers. Initial estimates of the spin-axis coupling coefficients for the dimers are 290 MHz for Rb; 2500 MHz for Cs.
We present an innovative fiber laser system for both cesium and rubidium manipulation. The architecture is based on frequency conversion of two lasers at 1560 nm and 1878 nm. By taking advantage of existing fiber components at these wavelengths, we demonstrate an all fiber laser system delivering 350 mW at 780 nm for rubidium and 210 mW at 852 nm for cesium. This result highlights the promising nature of such laser system especially for Cs manipulation for which no fiber laser system has been reported. It offers new perspectives for the development of atomic instruments dedicated to onboard ap…
我们开发了一个理论处理的偏振光谱，并用它来预测的一般形式的偏振光谱的碱金属原子。使用我们的模型，我们产生的理论光谱的D2跃迁在87 Rb，85 Rb，和133 Cs。实验表明，该模型准确地再现了从基态的上超精细能级跃迁的光谱。其中，闭合过渡F -> F' = F + 1占主导地位，具有通过线中心的陡峭梯度，理想地适合用作激光锁定中的参考。
We experimentally investigated Rabi resonance-based continuously frequency-tunable microwave (MW) magnetic field detection using a single hybrid vapor cell filled with cesium and rubidium atoms. The multispecies atomic systems, with their tunable abilities in transition frequencies, enabled this atomic sensing head to cover a broader detectable MW field scope compared to the use of a single metal atom. Here, we demonstrated the simultaneous observation of atomic Rabi resonance signals with 85Rb, 87Rb, and 133Cs in the same vapor cell. Using an experimentally feasible static magnetic field (DC …
Vapor cells with antirelaxation coating are widely used in modern atomic physics experiments due to the coating's ability to maintain the atoms' spin polarization during wall collisions. We characterize the performance of vapor cells with different coating materials by measuring longitudinal spin relaxation and vapor density at temperatures up to 95°C. We found that the spin-projection-noise-limited sensitivity for atomic magnetometers with such cells improves with temperature, which demonstrates the potential of antirelaxation coated cells in applications of future high-sensitivity magnetomet…
We present the results of a study on relaxation and diffusion processes of rubidium atoms in a rubidium cell with an internal vapor source. The cell is an evacuated glass bulb, which is characterized in that the source of atomic vapors in the form of a metal film Rb is evenly distributed throughout the inner surface of the bulb, and the paraffin film is uniformly distributed over the entire area and over the metal surface. By using laser optical pumping, we performed measurements of the relaxation time and the average number of bounces of optical pumped rubidium atoms in the bulb. We have meas…
I searched for the ground state 6.8 and 9.2 GHz hyperfine transitions of rubidium and cesium toward M- and L-dwarfs that show Rb and Cs optical resonance lines. The optical lines can pump the hyperfine transitions, potentially forming masers. These spin-flip transitions of Rb and Cs are the principal transitions used in atomic clocks (the $^{133}$Cs hyperfine transition defines the second). If they are detected in stellar atmospheres, these transitions would provide exceptionally precise clocks that can be used as accelerometers, as exoplanet detectors, as probes of the predictions of general …
We study radio-frequency spectrum of ellipticity noise of a probe laser beam transmitted through a cell with cesium vapor in a magnetic field. The experimental results are interpreted in terms of the model proposed by Gorbovitskii and Perel (Opt. Spektrosc. 54, 388 (1983)) according to which the observed noise arises due to heterodyning of the light scattered by fluctuations of the tensor $ α$ of optical susceptibility of cesium vapor. We show, both experimentally and theoretically, that, in the noise measurements if this kind, along with fluctuations of the antisymmetric (gyrotropic) part of …
We propose a new scheme for interrogating a warm rubidium vapor using two different clock lasers. Performance-wise, this approach is distinctly different from the recently proposed two-color two-photon rubidium clocks as our scheme does not trade off the AC Stark suppression against an increased sensitivity to the cell-temperature/pressure. Instead, our approach compensates all, the AC-Stark shift and the temperature & pressure-induced frequency shifts. The proposed scheme also makes use of the modulation transfer technique, which enables a two-orders of magnitude increase in the signal-to-noi…
We report on the observation of electromagnetically induced transparency (EIT) and absorption (EIA) of highly excited Rydberg states in thermal Cs vapor using a four-step excitation scheme. The advantage of this four-step scheme is that the final transition to the Rydberg state has a large dipole moment and one can achieve similar Rabi frequencies to two- or three-step excitation schemes using two orders of magnitude less laser power. This scheme enables new applications such as dephasing free Rydberg excitation. The observed lineshapes are in good agreement with simulations based on multileve…
We demonstrate the single-photon excitation spectra of cesium Rydberg atoms by means of a Doppler-free purely all-optical detection with a room-temperature vapor cell and a 319 nm ultra-violet (UV) laser. We excite atoms directly from 6S1/2 ground state to 71P3/2 Rydberg state with a narrow-linewidth 319 nm UV laser. The detection of Rydberg states is performed by monitoring the absorption of an 852 nm probe beam in a V-type three-level system. With a strong coupling light, we observe the Autler-Townes doublet and investigate experimentally the dependence of the separation and linewidth on the…
We report on studies of simultaneous continuous-wave mirrorless lasing on multiple optical transitions, realized by pumping hot cesium vapor with laser light resonant with the 6$S_{1/2}\rightarrow 8$P$_{3/2}$ transition. The multiplicity of decay paths for the excited atoms to their ground state is responsible for the emergence of lasing in a number of transitions, observed here in at least seven wavelengths in the infrared (IR), and at two wavelengths in the blue. We study the properties of the fields generated in the cesium vapor, such as optical power, directionality and optical linewidth.
The $6S_{1/2}-5D_{5/2}$ electric quadrupole transition is investigated in Cesium vapor at room temperature via nonlinear Doppler-free 6P-6S-5D three-level spectroscopy. Frequency-resolved studies of individual E2 hyperfine lines allow one to analyze optical pumping dynamics, polarization selection rules and line intensities. It opens the way to studies of transfer of light orbital angular momentum to atoms, and the influence of metamaterials on E2 line spectra.
We report on the storage of light via the phenomenon of Coherent Population Oscillation (CPO) in an atomic cesium vapor at room temperature. In the experiment the optical information of a probe field is stored in the CPO of two ground states of a Lambda three-level system formed by the Zeeman sublevels of the hyperfine transition F = 3 - F' = 2 of cesium D2 line. We show directly that this CPO based memory is very insensitive to stray magnetic field inhomogeneities and presents a lifetime which is mainly limited only by atomic motion. A theoretical simulation of the measured spectra was also d…
We demonstrate a single-photon Rydberg excitation spectroscopy of cesium (Cs) atoms in a room-temperature vapor cell. Cs atoms are excited directly from 6S1/2 ground state to nP3/2 (n = 70 - 100) Rydberg states with a 318.6 nm ultraviolet (UV) laser,and Rydberg excitation spectra are obtained by transmission enhancement of a probe beam resonant to Cs 6S1/2, F = 4 - 6P3/2, F' = 5 transition as partial population on F = 4 ground state are transferred to Rydberg state .Analysis reveals that the observed spectra are velocity-selective spectroscopy of Rydberg state, from which the amplitude and lin…
We have studied modification of the fluorescence spectra of a room-temperature atomic rubidium vapor in the region of $^{85}$Rb and $^{87}$Rb D$_2$ line while changing the temporal rate of linear (triangular) scanning of laser radiation frequency. Increase of the ramping speed over certain value ($\approx$ 10$^6$ MHz/s) results in essential modification of magnitudes of individual atomic transitions, different on rising and falling slopes, which characterize transition from a steady-state interaction regime to a transient one. Our experimental results are well consistent with the developed the…
We report on experimental and theoretical investigations of the polarization dependence of magnetic resonance generated by synchronous optical pumping. Magnetic resonances with narrow linewidth are generated experimentally using a rubidium vapor cell with octade-cyltrichlorosilane (OTS) antirelaxation coating on inner walls. We studied the effect of light ellipticity on the amplitudes and widths of magnetic resonances by matching the light modulation frequency with 2 Ω_L (alignment) and Ω_L(orientation) in a Bell-Bloom interaction geometry, where Ω_L corresponds to the Larmor frequency. Both 2…
We present experimental and numerical studies of nonlinear magneto-optical rotation (NMOR) in rubidium vapor excited with resonant light tuned to the $5^2\!S_{1/2}\rightarrow 6^2\!P_{1/2}$ absorption line (421~nm). Contrary to the experiments performed to date on the strong $D_1$ or $D_2$ lines, in this case, the spontaneous decay of the excited state $6^2\!P_{1/2}$ may occur via multiple intermediate states, affecting the dynamics, magnitude and other characteristics of NMOR. Comparing the experimental results with the results of modelling based on Auzinsh et al., Phys. Rev. A 80, 1 (2009), w…
Spatio-spectral vector light created by optical activity in rubidium vapor
University of Glasgow（格拉斯哥大学）；Fraunhofer UK Research Ltd.（弗劳恩霍夫英国研究有限公司）；Physikalisch-Technische Bundesanstalt（德国联邦物理技术研究院）；Technische Universität Braunschweig（布伦瑞克工业大学）
Spontaneous emission from individual atoms in vapor lasts nanoseconds, if not microseconds, and beatings in this emission involve only directly excited energy sublevels. In contrast, the superfluorescent emissions burst on a much-reduced timescale and their beatings involve both directly and indirectly excited energy sublevels. In this work, picosecond and femtosecond superfluorescent beatings are observed from a dense cesium atomic vapor. Cesium atoms are excited by 60-femtosecond long, 800 nm laser pulses via two-photon processes into their coherent superpositions of the ground 6S and excite…
We experimentally demonstrate a one-color two-photon transition from the $5\mathit{S}_{1/2}$ ground state to the $6\mathit{S}_{1/2}$ excited state in rubidium (Rb) vapor using a continuous wave laser at 993 nm. The Rb vapor contains both isotopes ($^{85}$Rb and $^{87}$Rb) in their natural abundances. The electric dipole allowed transitions are characterized by varying the power and polarization of the excitation laser. Since the optical setup is relatively simple, and the energies of the allowed levels are impervious to stray magnetic fields, this is an attractive choice for a frequency refere…
We investigate the phenomenon of optical bistability in a driven ensemble of Rydberg atoms. By performing two experiments with thermal vapors of rubidium and cesium, we are able to shed light onto the underlying interaction mechanisms causing such a non-linear behavior. Due to the different properties of these two atomic species, we conclude that the large polarizability of Rydberg states in combination with electric fields of spontaneously ionized Rydberg atoms is the relevant interaction mechanism. In the case of rubidium, we directly measure the electric field in a bistable situation via tw…
How to measure diffusional decoherence in multimode rubidium vapor memories?
扩散是热原子蒸气在空间多模式应用中存储时间的主要限制。系统中扩散退相干的精确知识对于设计大多数蒸气存储器设置是期望的。在这里，我们提出了一种新的，有效的和直接的方法来测量无偏扩散退相干，清楚地区别于所有其他的退相干源。我们得到了铷原子在惰性气体中的归一化扩散系数：氖0.20 cm $^{2}$ /s，氪0.068 cm $^{2}$ /s，并首次给出了铷在氙中的归一化扩散系数：0.057 cm $^{2}$ /s。我们的方法包括创建，存储和检索空间变化的原子相干性。拉曼散射提供了一个必要的界面，原子，允许探测许多空间周期性的原子相干性并发。与之前的实验相反，该方法可用于任何单个密封玻璃池，并且在测量期间不需要任何设置更改，因此它是鲁棒的和可重复的。
We have developed a torsion balance to detect the rotation of a cell containing spin-polarized gaseous atoms to study angular momentum transfer from gaseous atoms to solid. A cesium vapor cell was hung from a thin wire in a vacuum chamber, and irradiated from the bottom with circularly polarized light tuned to the $D_2$ transition to polarize cesium atoms in the cell. By varying the light helicity at the resonance frequency of the torsion balance, we induced forced rotational oscillation of the cell and detected radiation torque exerted on the cesium vapor cell through the cesium atoms inside.…
Compactness, robustness and autonomy of optical frequency references are prerequisites for reliable operation in mobile systems, on ground as well as in space. We present a standalone plug and play optical frequency reference device based on frequency modulation spectroscopy of the D2-transition in rubidium at 780 nm. After a single button press the hand-sized laser module, based on the micro-integrated laser-optical bench described in [J. Opt. Soc. Am. B 38, 1885-1891 (2021)], works fully autonomous and generates 6 mW of frequency stabilized light with a relative frequency instability of 1.4e…
Three body resonant interactions between Rydberg atoms are considered in order to perform few-body quantum gates. So far, the resonances found in cesium or rubidium atoms relied on an adjacent two-body resonance which ceases to exist for principal quantum numbers above $n \simeq 40$. We have proposed recently a new class of 3-body interaction resonances in alkali-metal Rydberg atoms [P. Cheinet \textit{et al.}, Quant. Elect. \textbf{50}, 213 (2020)], which circumvienes this limit. We investigate here the relative strength between this new class of 3-body interaction resonance and quasi-forbidd…
We present a new technique to measure pulsed magnetic fields based on the use of Rubidium in gas phase as a metrological standard. We have therefore developed an instrument based on laser inducing transitions at about 780~nm (D2 line) in a Rubidium gas contained in a mini-cell of 3~mm~x~3~mm cross section. To be able to insert such a cell in a standard high field pulsed magnet we have realized a fibred probe kept at a fixed temperature. Transition frequencies for both the $π$ (light polarization parallel to the magnetic field) and $σ$ (light polarization perpendicular to the magnetic field) co…
