  We recently demonstrated a continuous Bose-Einstein condensate of strontium
atoms. We could turn this into a continuous-wave atom laser if an efficient
outcoupling mechanism is found. Here we show a coherent three-photon excitation
of the clock transition in a strontium BEC with contrast of 44.6(3.5)%. We
follow it up with a demonstration of three-photon STIRAP-like transfer. Our
work constitutes an essential step towards the outcoupling of a continuous atom
laser beam and provides a robust excitation mechanism for quantum simulation.
