Resonance fluorescence in a waveguide geometry

We show how to calculate the first- and second-order statistics of the scattered fields for an arbitrary intensity coherent state light field interacting with a two-level system in a waveguide geometry. Specifically, we calculate the resonance fluorescence from the qubit, using input-output formalism. We derive the transmission and reflection coefficients, and illustrate the bunching and anti-bunching of light that is scattered in the forward and backward directions, respectively. Our results agree with previous calculations on one- and two-photon scattering as well as those that are based on the master equation approach.