Electroabsorption and electrooptic modulation in single crystal ZnSe-ZnSSe waveguides grown by OMVPE on GaAs

Electroabsorption and the electrooptical effect were used to modulate argon laser light in ZnSe single crystal waveguides. The electrical contacts were Schottky barriers that created a nonuniform electric field in the samples. The nonuniform electric fields are modeled, and the experimental results are matched to this model. The electroabsorption experiments showed a modulation depth of 9.2 dB at an applied voltage of 255 V and a wavelength of 476 nm. With the same applied voltage at lambda =488 nm the modulation depth was only 0.53 dB. Electrooptic phase modulation was also investigated. A phase shift of pi was found at 60 V for a sample of 3 mm length. The half wave voltage was independent of wavelength for wavelengths from 488 to 515 nm.>