Este trabalho relata o desenvolvimento de todo o aparato experimental para a realização de aprisionamento de césio através de uma armadilha magneto-óptica. As fontes de luz neste processo foram os lasers de diodo e todo seu sistema para operação, estabilização e redução da largura de linha foi construído. As medidas das constantes de mola e amortecimento foram realizadas como função dos parâmetros característicos das armadilhas de césio e de sódio. Também realizamos outros experimentos com átomos aprisionados de sódio na presença de duas freqüências, linha D1 e D2. A primeira medida constitui na obtenção da taxa de colisões entre átomos aprisionados na linha D1 e depois foi realizado observações de uma nova estrutura operando neste regime. / This thesis describes the development of a complete experimental setup for trapping cesium by a magneto-optical trap (MOT). In this work we have employed diode lasers as light sources and built the entire system for their operation, stabilization and linewidth reduction. We have measured the MOT spring and damping constants as functions of the characteristic parameters of the cesium and sodium traps. We have also carried out two other experiments on trapped sodium atoms operating in the simultaneous presence of the D1 and D2 line frequencies. The first experiment has established the collision rate of trapped atoms in the D1 line MOT and the second has allowed us to observe a new structure operating in this two-frequency regime.

Este trabalho relata o desenvolvimento de todo o aparato experimental para a realização de aprisionamento de césio através de uma armadilha magneto-óptica. As fontes de luz neste processo foram os lasers de diodo e todo seu sistema para operação, estabilização e redução da largura de linha foi construído. As medidas das constantes de mola e amortecimento foram realizadas como função dos parâmetros característicos das armadilhas de césio e de sódio. Também realizamos outros experimentos com átomos aprisionados de sódio na presença de duas freqüências, linha D1 e D2. A primeira medida constitui na obtenção da taxa de colisões entre átomos aprisionados na linha D1 e depois foi realizado observações de uma nova estrutura operando neste regime. / This thesis describes the development of a complete experimental setup for trapping cesium by a magneto-optical trap (MOT). In this work we have employed diode lasers as light sources and built the entire system for their operation, stabilization and linewidth reduction. We have measured the MOT spring and damping constants as functions of the characteristic parameters of the cesium and sodium traps. We have also carried out two other experiments on trapped sodium atoms operating in the simultaneous presence of the D1 and D2 line frequencies. The first experiment has established the collision rate of trapped atoms in the D1 line MOT and the second has allowed us to observe a new structure operating in this two-frequency regime.

What if an elementary particle such as an electron had an intrinsic electric dipole moment (EDM)? Existence of such an EDM would be an indication of time-reversal symmetry violation in the laws of Physics. The Standard model of Physics is considered incomplete, and theories that go beyond the standard model predict existence of such EDM’s within experimental reach. Experiments that search for their existence serve as a test bed for these theories. Use of laser-cooled Yb atoms launched in a fountain for EDM search has been proposed earlier. This thesis describes the main experimental work on generating a continuous cold beam of Yb atoms using laser cooling. Such cold beams are ideal for performing EDM experiments and have several advantages over the more common pulsed fountain. We demonstrate two ways to achieve this (i) extracting the beam from atoms trapped in 2- dimensions and (ii) deflecting the atomic beam using 1D-optical molasses. We find that the latter method gives a longitudinal temperature of 41 mK, which is a factor of 3 better than the former one. We also demonstrate the implementation of Ramsey’s separated oscillatory field technique in a thermal beam to measure the larmor precession frequency with high precision. This serves as a first step towards implementation with cold beam. Extending the work reported here, we suggest future experiment for measuring an EDM.

This thesis presents a new optical imaging technique which measures the structure of objects without the use of lenses. Termed diffraction-contrast imaging (DCI), the method retrieves the object structure from a Fresnel diffraction pattern of the object, using a deconvolution algorithm. DCI is particularly adept at imaging highly transparent objects and this is demonstrated by retrieving the structure of an almost transparent cloud of laser-cooled atoms. Applied to transparent Bose-Einstein condensates, DCI should allow the non-destructive imaging of the condensate while requiring only the minimum possible apparatus of a light source and a detector. (For complete abstract open document)