Abstract: The present invention is a method and apparatus for creating a narrow linewidth hybrid semiconductor laser using silicon-oxide and silicone-oxynitride based external feedback elements. These feedback elements use Bragg gratings formed by periodic variation of the refractive index with a resonate optical reflector. The laser has a narrow linewidth (in the tens of kHz range), which can be accurately tunable to facilitate locking to an ultra-stable cavity.

Abstract: When embodied in a microgyroscope, the invention is comprised of a silicon, four-leaf clover structure with a post attached to the center. The whole structure is suspended by four silicon cantilevers or springs. The device is electrostatically actuated and capacitively detects Coriolis induced motions of the leaves of the leaf clover structure. In the case where the post is not symmetric with the plane of the clover leaves, the device can is usable as an accelerometer. If the post is provided in the shape of a dumb bell or an asymmetric post, the center of gravity is moved out of the plane of clover leaf structure and a hybrid device is provided. When the clover leaf structure is used without a center mass, it performs as a high Q resonator usable as a sensor of any physical phenomena which can be coupled to the resonant performance.

Abstract: An improved optical gyroscope is provided, of the type that passes two light components in opposite directions through an optic fiber coil, and which adds a small variable frequency to one of the light components to cancel the phase shift due to rotation of the coil. The amount of coil rotation from an initial orientation, is accurately determined by combining the two light components, one of which has a slightly increased frequency, to develop beats that each represent a predetermined angle of rotation. The direction of rotation is obtained by combining the two light components on a photodetector, intermittently phase shifting a single light component by 90.degree., and comparing the direction of change of photodetector output (+ or -) caused by the 90.degree. shift, with the slope (+ or -) of the photodetector output at about the same time, when there is a 90.degree. shift.