Patent ID: 8406575

Claim:
An optoelectronic apparatus comprising: an optical waveguide with a variable refractive index; and an active device comprising a junction field effect transistor (JFET) formed within the optical waveguide, said active device comprising: a first region of a first doping type, comprising: a drain terminal; a source terminal; and a conductive channel between the source and drain terminals, through which current flows perpendicular to light passing through the optical waveguide; a background concentration of free carriers introduced by application of a majority carrier bias current through the conductive channel; a second region of a second doping type comprising a gate terminal modulating the variable refractive index affecting light traveling through said optical waveguide by modulating spatial distribution of the free carriers within the optical waveguide; wherein the second doping type is a reverse polarity of the first doping type; wherein one of the doping types is a p-type, including a region of uniform semiconductor composition with band gap large enough to permit high optical transmission at a wavelength of operation; wherein only majority carriers are modulated by the gate terminal; and a depletion region formed at a junction between the first region and the second region.