We study two-photon transport in a one-dimensional waveguide with a side-coupled two-level system. Depending on the momentum of the incoming photons, we find that the nature of the scattering process changes considerably. We further show that bunching behavior can be found in the scattered light. As a result, we find that the waveguide dispersion has a strong influence on the photon correlations. By modifying the momentum of the pulse, the nature of the correlations can therefore be altered or optimized.

We present a theoretical analysis of pulse propagation in a waveguide with a side-coupled Kerr nonlinear cavity. As a specific application, we demonstrate how the nonlinearity has a profound influence on transport properties of a photon-added coherent state. We find that the fields provided by the coherent states facilitate a tunable nonlinearity on the few-photon level, allowing for a robust gating of single photons.

The Hong-Ou-Mandel effect is studied in the context of two-photon transport in a one-dimensional waveguide with a single scatterer. We numerically investigate the scattering problem within a time-dependent, wave-function-based framework. Depending on the realization of the scatterer and its properties, we calculate the joint probability of finding both photons on either side of the waveguide after scattering. We specifically point out how Hong-Ou-Mandel interferometry techniques could be exploited to identify effective photon–photon interactions which are mediated by the scatterer.