ABSTRACT:
An optical magnetometer is disclosed. The device includes a cell filled with a substance that has a magnetic moment, such as an alkali metal. First and second light sources, typically diode lasers, illuminate the cell, one optically pumping the cell and one probing the cell. The two diode lasers are set to emit light at two distinct wavelengths, one set to drive a first transition and the other set to drive a second transition within the substance filling the cell. The probe laser light transiting the cell is used to modulate the frequency of the probe laser. The two beams of light are polarized with an ellipticity of at least 0.3.

ABSTRACT:
A quantum mechanical measurement device is provided. A spin ensemble is provided. A first light source provides a first light at a first wavelength, wherein the first light source is positioned to provide light into the spin ensemble. A detector is positioned to detect light from the spin ensemble. A modulator modulates absorption of the first light from the first light source by the spin ensemble at a frequency greater than a Larmor frequency of the spin ensemble.

ABSTRACT:
A flexible and relatively simple and cheap optical dipole mirror for cold rubidium atoms from magneto-optical trap is described, being a very modern and efficient tool for atomic physicists. Emphasis is put on physical processes responsible for the mirror parameters and their optimization. Promising perspectives are provided for evanescent wave properties investigation and atom–surface interaction measurements.

ABSTRACT:
The first part of this thesis concerns an experimental and theoretical study of the atomic spatial distributions in a magneto-optical trap generated by means of radiative vortex forces. With a diaphragm it is possible to vary the waist and power of one of the cooling laser beams and change parameters of large-diameter, parallelogram-shaped atomic orbits called atomotrons. The computer simulations of atomic trajectories (based on the mathematical model of the vortex forces) explained the observed spatial structures, and I employed these simulations to present potential applications of controlling radiative vortex forces by means of laser beam waist and power manipulations. In the second part of the dissertation there is described the experiment in the optical mirror set-up. The experimental set-up fulfilled conditions for which the good quality quantitative results were possible. The analysis of the parameters of the spatial density distributions of the reflected atoms enabled to obtain information about some characteristics of the optical mirror used in the experiment. Those data may have practical meaning in the future experiment in which the optical mirror set up will be used.

ABSTRACT:
We present an experimental and theoretical study of controlling the atomic spatial distributions in a magneto-optical trap (MOT). With a diaphragm we can vary the waist and power of one of the cooling laser beams and we can change parameters of large-diameter, parallelogram-shaped atomic orbits. We show that the radiative force generated by the repumping MOT laser has to be taken into consideration. Computer simulations of atomic trajectories explain the observed spatial structures, and we employ these simulations to present potential applications of controlling the diaphragm diameter as a function of time. A potential use of controlled vortex forces seems to have a great significance in recently presented important new methods to investigate cold atom collisions in the MOT, which were recently published.

ABSTRACT:
Optical pumping of helium makes use of the 2 3S–2 3P transition at 1083 nm. We report on a study of this transition in magnetic fields up to 1.5 T. Based on these results, an optical method to measure nuclear polarisation in arbitrary field has been developed. Preliminary results on optical pumping at 0.1 T are presented.

ABSTRACT:
The structure of the excited 23S and 23P triplet states of 3He and 4He in an applied magnetic field B is studied using different approximations of the atomic Hamiltonian. All optical transitions (line positions and intensities) of the 1 083 nm 23S- 23P transition are computed as a function of B. The effect of metastability exchange collisions between atoms in the ground state and in the 23S metastable state is studied, and rate equations are derived, for the populations these states in the general case of an isotopic mixture in an arbitrary field B. It is shown that the usual spin-temperature description remains valid. A simple optical pumping model based on these rate equations is used to study the B-dependence of the population couplings which result from the exchange collisions. Simple spectroscopy measurements are performed using a single-frequency laser diode on the 1 083 nm transition. The accuracy of frequency scans and of measurements of transition intensities is studied. Systematic experimental verifications are made for B = 0 to 1.5 T. Optical pumping effects resulting from hyperfine decoupling in high field are observed to be in good agreement with the predictions of the simple model. Based on adequately chosen absorption measurements at 1 083 nm, a general optical method to measure the nuclear polarisation of the atoms in the ground state in an arbitrary field is described. It is demonstrated at B∼ 0.1 T, a field for which the usual optical methods could not operate.

ABSTRACT:
We have observed changes in the polarization of an evanescent wave propagating in a resonant atomic vapor. The effect can be interpreted as an effective dichroism and birefringence of the vapor, the phenomenon characteristic of anisotropic media. In this case it arises from the Goos-Hänchen shift, which is different for light polarized parallel and perpendicular to the incident plane. We have also observed Faraday rotation of the evanescent wave.

ABSTRACT:
An evanescent light penetrating an atomic vapour near a dielectric surface could be a probe for many atom-boundary phenomena. We show the possibility of very sensitive detection of the resonant atom–light interaction near the surface by using the optogalvanic effect for an evanescent wave. We observe a narrowing of the profile of the detected atomic line, and we point out some properties of the optogalvanic effect in the evanescent wave.