The observation of infrared emission between superlattice conduction minibands is reported. Electrons resonantly injected into the first excited state miniband by an applied electric field make a radiative transition to the ground state miniband. The spectra are dominated by direct high oscillator strength transitions at the mini-Brillouin zone edge and the peak wavelength can be tailored over a broad infrared range by designing the superlattice minigap. At high bias, the spectra extend to wavelengths corresponding to transitions from high lying states near the mini-Brillouin zone center. Experiments in AlInAs/GaInAs superlattices have demonstrated peak luminescence wavelengths of &lgr;=5 and 7 &mgr;m. At high currents, the spectra broaden to shorter wavelengths (down to 3 &mgr;m) as electrons are tunnel injected high into the second miniband. ©1997 American Institute of Physics.