  Quantum dots in cavities have been shown to be very bright sources of
indistinguishable single photons. Yet the quantum interference between two
bright quantum dot sources, a critical step for photon based quantum
computation, has never been investigated. Here we report on such a measurement,
taking advantage of a deterministic fabrication of the devices. We show that
cavity quantum electrodynamics can efficiently improve the quantum interference
between remote quantum dot sources: poorly indistinguishable photons can still
interfere with good contrast with high quality photons emitted by a source in
the strong Purcell regime. Our measurements and calculations show that cavity
quantum electrodynamics is a powerful tool for interconnecting several devices.
