Quantum Manipulation of Multi-Photon States of Light

After a brief introduction of the main theoretical concepts of quantum optics, this work presents the experimental techniques used in laboratory to implement the fundamental operations of adding and subtracting a single photon on/from an arbitrary state of light. Then it is shown how to combine these thechniques in order to obtain more complex quantum transformations. The results of two experiments are presented. In the first one, the possibility of emulating the effects of a strong Kerr non-linearity on a weak quantum state is demonstrated, in the second one it is shown that the delocalized addition of a single photon on two optical modes can entangle them, even if they are macroscopically populated.