  We study the properties of an atom laser beam derived from a Bose-Einstein
condensate using three different outcouplers, one based on multi-state radio
frequency transitions and two others based on Raman transitions capable of
imparting momentum to the beam. We first summarize the differences that arise
in such systems, and how they may impact on the use of an atom laser in
interferometry. Experimentally, we examine the formation of a bound state in
all three outcouplers, a phenomenon which limits the atom laser flux, and find
that a two-state Raman outcoupler is the preferred option for high flux, low
divergence atom laser beams.
