We have studied the electronic structure of strained-layer ZnSe/ZnS su
perlattices by using two kinds of two-photon spectroscopy: two-photon
absorption spectroscopy and resonant second-harmonic generation. The e
xciton binding energy is found to exhibit a blue shift as compared to
the bulk value due to the exciton confinement effect. Based on the obs
erved subband energies, we derive a conduction-band offset of approxim
ately 70 meV and a valence-band offset of approximately 800 meV.