ZnSe-based electro-optic waveguide modulators for the blue-green spectral range

The Pockels effect is used to modulate and switch blue-green light by means of MBE-grown ZnSe waveguides with cladding layers of (Zn,Mn)Se on n-GaAs substrates. In a retarder geometry, the strained birefringent planar waveguide exhibits a contrast ratio larger than 80:1 at 2.485 eV. When the electric field is applied via stripe contacts on the top cladding layer, the waveguiding for TE-polarized light can be confined in the lateral direction. In the centre of the lateral waveguide channel, the contrast ratio is better than 16:1 at 2.48 eV. Switching between adjacent channels is demonstrated with a contrast ratio better than 5:1.