  Entangled two-photon spectroscopy is expected to provide advantages compared
with classical protocols. It is achieved by coherently controlling the spectral
properties of energy-entangled photons. We present here an experimental setup
that allows the spectral shaping of entangled photons with high resolution. We
evaluate its performances by detecting sum frequency generation in a non-linear
crystal. The efficiency of the process is compared when performed with
classical or entangled light.
