| Abstract: | An apparatus for optical modulation is provided. The apparatus includes a
modulator structure and a heater structure. The modulator structure
comprises a ring or disk optical resonator having a closed curvilinear
periphery and a pair of oppositely doped semiconductor regions within
and/or adjacent to the optical resonator and conformed to modify the
optical length of the optical resonator upon application of a bias
voltage. The heater structure comprises a relatively resistive annulus of
semiconductor material enclosed between an inner disk and an outer
annulus of relatively conductive semiconductor material. The inner disk
and the outer annulus are adapted as contact regions for a heater
activation current. The heater structure is situated within the periphery
of the optical resonator such that in operation, at least a portion of
the resonator is heated by radial conductive heat flow from the heater
structure. The apparatus further includes a substantially annular
isolation region of dielectric or relatively resistive semiconductor
material interposed between the heater structure and the modulator
structure. The isolation region is effective to electrically isolate the
bias voltage from the heater activation current. |