Abstract

In general, the semiconducting electrooptical devices based on the Integrated Optics technology, present a low doped guiding region where the electric field is applied. This region is sandwiched between to highly doped (or metallic) media which permit to apply this field |1|. The smaller the thickness of this guiding region is, the lower the drive voltage is but the higher the propagation losses are because of a more important overlap between the optical mode and the free carriers of the extreme media. Moreover in the mid-infrared region, this influence of free carriers on propagation losses in semiconductors is very important. So, a trade-off has to be found to combine low losses and low drive voltage that have up to now only been demonstrated separately |2|, |3|, |4|. The phase modulator described below has been realized to optimize both parameters simultaneously. This device is based on a two-dimensional waveguide and presents together performances below 2 dB/cm and around 100 Volts for the propagation losses and the drive voltage V_π respectively.

© 1988 Optical Society of America