The first part of this thesis concerns the development of a novel type of Zeeman slower (ZS) that is based on permanent magnets and has several advantages over the conventional ZS. We present the performances of the apparatus for two different magnet configurations: the dipole and Halbach configurations. The second part is about scattering experiments of guided matter waves on a complex potential. After describing the experimental setup that produces Bose-Einstein condensates in a crossed dipole trap, we report on three experiments. The first experiment studies the scattering of a matter wave on a finite size optical lattice that forms a Bragg reflector. We discuss the processes involved in the scattering and we study in detail the transmissivity across the Bragg mirror. We then demonstrate the trapping of a propagating Bose-Einstein condensate in a Bragg cavity that originates from the envelope of the lattice. We observe oscillations inside the cavity and partial tunneling out of the cavity for narrow classes of velocity. This technique allows to characterize new types of tunnel barriers in position space equivalent to submicronic repulsive barriers. Finally, we study the scattering of matter waves on an amplitude-modulated optical lattice, and analyse the transmissivity across this structure when varying the modulation frequency. We describe the complex dynamics at play within the Floquet-Bloch framework and the use of this technique to realize a new type of tunable velocity filter. This filter does not rely on any specific internal state configuration.
