  The interference of photons emitted by dissimilar sources is an essential
requirement for a wide range of photonic quantum information applications. Many
of these applications are in quantum communications and need to operate at
standard telecommunication wavelengths to minimize the impact of photon losses
and be compatible with existing infrastructure. Here we demonstrate for the
first time the quantum interference of telecom-wavelength photons from an
InAs/GaAs quantum dot single-photon source and a laser; an important step
towards such applications. The results are in good agreement with a theoretical
model, indicating a high degree of indistinguishability for the interfering
photons.
