A laser system for efficient exitation of positronium towards Rydberg levels

Antihydrogen production by charge exchange between positronium atoms in Rydberg levels and antiprotons is predicted to be much more effective than the direct recombination of positrons and antiprotons. Here we present a pulsed laser system suited for the two step positronium excitation n=1 -> n=3 (wavelength of 205 nm) and n=3 -> n=20 ... 30 (wavelength of about 1670 nm), and with spectral properties suited to account for the various broadening mechanisms typically present in experiments dealing with cold antimatter.