  A silicon quantum photonic circuit was proposed and demonstrated as an
integrated quantum light source for telecom band polarization entangled Bell
state generation and dynamical manipulation. Biphoton states were firstly
generated in four silicon waveguides by spontaneous four wave mixing. They were
transformed to polarization entangled Bell states through on-chip quantum
interference and quantum superposition, and then coupled to optical fibers. The
property of polarization entanglement in generated photon pairs was
demonstrated by two-photon interferences under two non-orthogonal polarization
bases. The output state could be dynamically switched between two polarization
entangled Bell states, which was demonstrated by the experiment of simplified
Bell state measurement. The experiment results indicate that its manipulation
speed supported a modulation rate of several tens kHz, showing its potential on
applications of quantum communication and quantum information processing
requiring dynamical quantum entangled Bell state control.
