The ability to manipulate quantum states of light by integrated devices may open new perspectives both for
fundamental tests of quantum mechanics and for novel technological applications. The technology for handling
polarization-encoded qubits, the most commonly adopted approach, was still missing in quantum optical circuits
until the ultrafast laser writing (ULW) technique was adopted for the first time to realize integrated devices able
to support and manipulate polarization encoded qubits.1 Thanks to this method, polarization dependent and independent
devices can be realized. In particular the maintenance of polarization entanglement was demonstrated
in a balanced polarization independent integrated beam splitter1 and an integrated CNOT gate for polarization
qubits was realized and carachterized.2 We also exploited integrated optics for quantum simulation tasks: by
adopting the ULW technique an integrated quantum walk circuit was realized3 and, for the first time, we investigate
how the particle statistics, either bosonic or fermionic, influences a two-particle discrete quantum walk.
Such experiment has been realized by adopting two-photon entangled states and an array of integrated symmetric
directional couplers. The polarization entanglement was exploited to simulate the bunching-antibunching
feature of non interacting bosons and fermions. To this scope a novel three-dimensional geometry for the waveguide
circuit is introduced, which allows accurate polarization independent behaviour, maintaining a remarkable
control on both phase and balancement of the directional couplers.