  We present experimental and theoretical results showing the improved beam
quality and reduced divergence of an atom laser produced by an optical Raman
transition, compared to one produced by an RF transition. We show that Raman
outcoupling can eliminate the diverging lens effect that the condensate has on
the outcoupled atoms. This substantially improves the beam quality of the atom
laser, and the improvement may be greater than a factor of ten for experiments
with tight trapping potentials. We show that Raman outcoupling can produce atom
lasers whose quality is only limited by the wavefunction shape of the
condensate that produces them, typically a factor of 1.3 above the Heisenberg
limit.
