An integrated optical device is disclosed comprising a substrate, optical
waveguide, and compound optical resonator having a temperature sensor, at
least two coupled optical resonators, and a heater localized to each
optical resonator. An optical input signal is coupled to one of the
resonators making up the compound resonator to form an optical output
signal. The center wavelength and shape of the output signal is optimized
with a feedback loop using the temperature sensor to control the power
dissipated in at least one of the localized heaters. The power dissipated
in the remaining resonator heaters is set according to a predetermined
function having as an input variable the power dissipated in the resonant
heater under control of the said feedback loop.