Field-dependent optical properties of wide band gap type II ZnSe/BeTe superlattices (SLs) are investigated by photoluminescence and electroreflectance. For a 40-Å period SL, lattice matched to GaAs, the lowest spatially indirect transition is found in the visible spectral range at 2.04 eV at room temperature. By application of external voltages, U ext shifts of the transition up to 65 meV are demonstrated. The series of electroreflectance spectra for different U ext shows spatially indirect as well as direct transitions. An optical layer stack model allows a quantitative description. Furthermore, electric field-dependent resonant Raman spectroscopy of confined optical phonons is applied to investigate the shape of a tunneling hole wave function in ZnSe. The shape is found to be very sensitive to applied electric fields.