Abstract

Progress of optical modulators made of semiconductor material are expected for further development of opto-electronics. A new type of optical modulator based on electron depleting absorption control (EDAC) has been proposed by authors,^1,2 for that purpose. In an impurity doped direct-transition-type semiconductor material, optical absorption is enhanced by depleting the carriers, through three physical phenomena induced in the depleting region: (1) a decrease in the number of electrons (or holes) located in the conduction (or valence) band resulting in increase of the band-to-band and the band-to-impurity-atom transition probabilities, (2) a decrease of the screening effect on the ionized-impurity atoms resulting in shift of the impurity energy levels, and (3) an increase of the electric field in the depletion layer inducing Franz-Keldysh effect.

© 1994 Optical Society of America