Carlos. This thesis would not have been possible unless the help of briliant individuals who really enriched my two years stay in Brazil.I am using this opportunity to express my gratitude to everyone who supported me throughout the course. Foremost, I owe my deepest gratitude to my supervisors, Prof.Vanderlei S. Bagnato specially for giving me a unique opportunities to do research in AMO Physics laboratory and helping me to come up with this thesis, without his support this project would not have been possible. I am also deeply grateful to Prof. Emanuel Henn, his persistent help lessened burden of writing this thesis. I am thankful for his aspiring guidance. I am indebted to many of my colleagues who I received endless support from. A special acknowledgement goes to our research members at "BECI" experiment Gustavo Telles, Rodrigo Shiozaki, Pedro Tavares, Guilherme Bagnato, Amilson Fritsch, Áttis Vinícius and Yuri Tonin. It was a pleasure to be a part of your team guys. I also appreciate the huge amount of support from Giacomo Roati who helped us a lot to push the work ahead.Those people who provided me a needed form of help, also deserve thanks. I express my warm thanks to my colleagues