We demonstrate a method for time gating the standard heralded continuouswave (cw) spontaneous parametric down-converted (SPDC) single photon source by using pulsed pumping of the optical parametric oscillator (OPO) below threshold. The narrow bandwidth, high purity, high spectral brightness and the pseudo-deterministic character make the source highly suitable for light-atom interfaces with ato...

We report the realisation and preliminary study of a frequency standard using a fountain of laser cooled caesium atoms. Our apparatus uses a magneto-optical trap as a source of cold atoms and optical pumping to prepare the atoms in the correct state before they enter the microwave cavity.

The structure of the excited 2S and 2P triplet states of He and He in an applied magnetic field B is studied using different approximations of the atomic Hamiltonian. All optical transitions (line positions and intensities) of the 1083 nm 2S-2P transition are computed as a function of B. The effect of metastability exchange collisions between atoms in the ground state and in the 2S metastable s...

We present a theoretical study of the spectra produced by optical/radio-frequency double resonance devices, in which resonant linearly polarized light is used in the optical pumping and detection processes. We extend previous work by presenting algebraic results which are valid for atomic states with arbitrary angular momenta, arbitrary rf intensities, and arbitrary geometries. The only restric...

We theoretically show that a sequence of short laser pulses can efficiently polarize nuclear-spin of atoms/ions. This is a variant of optical pumping with an important difference that a sequence of short laser pulses is used instead of a continuous-wave laser. Such a replacement is particularly useful if the pumping wavelength is in the ultraviolet or vacuum-ultraviolet region where obtaining a...

This paper presents the nonlinear dynamics of laser cooled and trapped cesium atoms placed inside an optical cavity and interacting with a probe light beam slightly detuned from the 6S1/2F = 4 to 6P3/2F = 5 transition. The system exhibits very strong bistability and instabilities. The origin of the latter is found to be a competition between optical pumping and non-linearities due to saturation...

In this paper, considering optical feedback as an optical injection, and taking in to account round-trip time role in the external cavity, a standard small signal analysis is applied on laser rate equations. By considering the relaxation oscillation (f2) and external cavity frequencies (f) ratio for semiconductor laser, field amplitude response gain, optical phase and carrier number for long ex...

We describe an efficient method for transporting and rearranging mesoscopic objects in three dimensions using short repetitive sequences of holographic optical trapping patterns. Material transport in this process is analogous to peristaltic pumping, with the configurations of optical traps mimicking the states of a physical peristaltic pump. Optical peristalsis can transport large numbers of s...

Laser Dynamics 12 Laser Dynamics S. Dangel, A. Schneider, R. Holzner A main part of our research activities, besides the laser related projects described in the section on surface physics, is the investigation of nonlinear spatio-temporal e ects caused by the interaction of resonant laser beams with sodium atoms in the gas phase. A circularly polarized laser beam propagating through sodium vapo...

2014 Samples of optically pumped 23S1 helium atoms are currently studied in our laboratory for use in advanced magnetometer applications. The results of recent investigations of the effect of pumping beam orientation with respect to the observed magnetic field are presented in this paper. The orientation dependence of the amplitude and frequency of the magnetic resonance signal observed by opti...