  We present an integrated source of counterpropagating entangled states based
on a coupled resonator optical waveguide that is pumped by a classical pulsed
source incident from above the waveguide. We investigate theoretically the
generation and propagation of continuous variable entangled states in this
coupled-cavity system in the presence of intrinsic loss. Using a tight-binding
approximation, we derive analytic time-dependent expressions for the number of
photons in each cavity, as well as for the correlation variance between the
photons in different pairs of cavities, to evaluate the degree of quantum
entanglement. We also derive simple approximate expressions for these
quantities that can be used to guide the design of such systems, and discuss
how pumping configurations and physical properties of the system affect the
photon statistics and the degree of quantum correlation.
