The QUASIX project aims at designing, fabricating and exprimentally validating the prototype of a new generation silicon-based integrated single photon source for quantum communications, quantifiable as a radically innovative technology.

Commercial QKD systems are generally based on discrete components obtaining single photon impulses by radiative deexcitation in a quantum system. Different solutions have also been developed to integrate "native" generation and detection of single photons and their polarization states on different materials, such as silica-on-silicon, III-V semiconductors, diamond and photonic crystals.

The demands on a unifying earth-space technology are many: compatibility between optical fiber and air, speed, tolerance to thermal dilation, room temperature operation, etc.

Still, silicon-only integrated solutions satisfying all of those demands are not currently commercially available. A direct silicon integration would directly combine together the advantages and knowledge of control electronics based on sub-micron CMOS technology with those deriving from the integration of photonic components in silicon, thus reducing losses due to the coupling between photon sources and integrated photonic circuits, nontheless lowering costs and gaining efficiency.

Finally, employment of silicon itself would allow to handle the mismatch due to thermal dilation which would be present if the source was made of a different material joined with silicon (i.e. through flip-chip).

Development of a winning solution entirely based on silicon requires the interrelation between different actors operating in different disciplinary fields, ranging from material science to QKD protocols.