Integrated resonant micro-optical gyroscope and method of fabrication

An integrated optic gyroscope, comprising:

• (a) a passive ring resonator formed on a first substrate, with the passive ring resonator further comprising:
• (i) a coiled optical waveguide having a plurality of loops;
• (ii) a pair of input optical waveguides optically coupled to the coiled optical waveguide to receive lasing light from an edge of the first substrate and to convey the lasing light into the coiled optical waveguide in each of two counterpropagating directions;
• and
• (iii) a pair of output optical waveguides optically coupled to the coiled optical waveguide to receive a portion of the lasing light out from the coiled optical waveguide and to convey the portion of the lasing light to the edge of the first substrate after propagating around the coiled optical waveguide;
• and
• (b) a photonic integrated circuit formed on a second substrate, and further comprising:
• (i) a bidirectional distributed feedback (DFB) laser to generate the lasing light and to emit the lasing light from each end thereof;
• (ii) a pair of optical waveguide phase modulators optically coupled to each end of the DFB laser to provide a phase modulation for the lasing light;
• (iii) a passive optical waveguide to convey the lasing light from each optical waveguide phase modulator to an edge of the second substrate wherefrom the lasing light is coupled into the input optical waveguides on the first substrate;
• and
• (iv) a waveguide photodetector to receive the portion of the lasing light from each output optical waveguide on the first substrate and to generate therefrom an electrical output signal indicative of a rotation rate of the passive ring cavity.

A method for forming an integrated optic gyroscope, comprising steps for:

• (a) epitaxially growing on a compound semiconductor substrate a plurality of compound semiconductor layers including at least one quantum well layer;
• (b) forming a plurality of active optical elements from the compound semiconductor layers including a bidirectional laser source and a pair of waveguide photodetectors;
• (c) disordering or etching away a portion of the compound semiconductor layers and forming therefrom a pair of optical waveguide phase modulators optically coupled to the bidirectional laser source and a plurality of passive optical waveguides, with the passive optical waveguides connecting the pair of the optical waveguide phase modulators and the pair of waveguide photodetectors to an edge of the compound semiconductor substrate;
• and
• (d) connecting a passive ring resonator to the edge of the compound semiconductor substrate, with the passive ring resonator being optically coupled to the plurality of passive optical waveguides to receive a phase-modulated lasing output from the laser source and each optical waveguide phase modulator, and to direct a portion of the phase-modulated lasing output to each waveguide photodetector after propagating the phase-modulated lasing output around the passive ring resonator.