We demonstrate a magneto-optical trap （MOT） with counter-propagating two-color cooling beams in a cesium 6S1/2 - 6P3/2 - 8S1/2 （852.3 ＋ 794.6 nm） atomic system. Based on the conventional MOT due entirely to the 852.3 nm cooling laser＇s scattering forces, we replace one of the six 852.3 nm cooling beams with a 794.6 nm cooling beam. Our two-color MOT can efficiently cool and trap atoms from the red to blue detuning sides of two-photon resonance without pre-cooling, The technique is promising for the direct generation of correlated photon pairs in a two-color MOT based on diamond-configuration four-wave mixing.
A single atom in a magneto--optical trap （MOT） with trap size （hundreds of micrometers） can be transferred into an optical microscopic tweezer with a probability of -100%, The ability to transfer a single atom into two traps back and forth allows us to study the loading process. The loading probability is found to be insensitive to the geometric overlap of the MOT and the tweezer. It is therefore possible to perform simultaneously loading of a single atom into all sites of the tweezer array for many qubits. In particular, we present a simulation of the one-dimensional and two-dimensional arrays of an optical microscopic tweezer. We find the same qualitative behavior for all of the trap parameters.
We experimentally demonstrate efficient frequency doubling of a telecom 1560 nm distributed feedback diode laser with a 3 cm long MgO：PPLN waveguide with a conversion coefficient of 114%/W. We investigate optical inhomogeneities by measuring the quasi-phase-matching temperature curve. The -2.7 mW of second-harmonic power at 780 nm is sufficient to detect the Rb D2 features using modulation transfer spectroscopy. The laser frequency is locked to a hyperfine transition of Rb D2 line and typical residual frequency fluctuation of ＋86 kHz （rms） is achieved within 30 min. Our experimental scheme can be used for realizing robust, compact, and highly accurate Rb stabilized 1560 nm laser systems for fiber-optic communication applications.
We report the realization of a deterministic single-atom preparation by the method of all-optical feedback. Using a fast-real-time feedback, the light-induced atom desorption effect and blue detuned light-induced atom collision process can increase a success probability of single-atom preparation up to more than 99%. We investigate the dynamics of loading single atom trapped in a trap with a size of hundreds of micrometers into a pair of microscopic tweezers. The detailed experimental results show that the feedback loading is spatially insensitive, which implies that it is possible to use the feedback protocol to simultaneously implement the loading of large number of qubits arrays.
We present a pair of phase-locked lasers with a 9.2-GHz frequency difference through the injection locking of a master laser to the RF-modulation sideband of a slave diode laser. Using this laser system, a coherent population trapping （CPT） signal with a typical linewidth of ～ 182 Hz is obtained in a cesium vapor cell filled with 30 Torr （4kPa） of neon as the buffer gas. We investigate the influence of the partial pressure of the neon buffer gas on the CPT linewidth, amplitude, and frequency shift. The results may offer some references for CPT atomic clocks and CPT atomic magnetometers.
