In this paper we report the first waveguide modulator, grown on a GaAs
substrate by molecular beam epitaxy, to use an undoped ZnSe/ZnCdSe mu
lti quantum well structure as the guiding layer with doped ZnSe layers
acting as the surrounding cladding. The quantum confined Stark effect
was observed in this device and used to produce an intensity modulati
on at wavelengths of 496 and 501 nm. A transverse linear electro-optic
effect was also observed as a superimposed secondary effect on the in
tensity modulation at 514 nm in the form of phase modulation in the ou
tput of the same device.