An integrated optic gyroscope is disclosed which is based on a photonic integrated circuit (PIC) having a bidirectional laser source, a pair of optical waveguide phase modulators and a pair of waveguide photodetectors. The PIC can be connected to a passive ring resonator formed either as a coil of optical fiber or as a coiled optical waveguide. The lasing output from each end of the bidirectional laser source is phase modulated and directed around the passive ring resonator in two counterpropagating directions, with a portion of the lasing output then being detected to determine a rotation rate for the integrated optical gyroscope. The coiled optical waveguide can be formed on a silicon, glass or quartz substrate with a silicon nitride core and a silica cladding, while the PIC includes a plurality of III V compound semiconductor layers including one or more quantum well layers which are disordered in the phase modulators and to form passive optical waveguides.

Simple passive ring resonator laser gyro. The gyro eliminates the need to separately control the frequency of the two oppositely directed beams. The gyro eliminates the need to alternatively switch the light source at fixed steps of time between the two frequencies at which each of the oppositely directed beams are in resonance. A semiconductor laser diode, the beam source, is locked to one signal and its output is coupled into a closed geometric shape waveguide resonator and then sampled by detectors. The laser beam is maintained at the resonant frequency of one of the directions of propagation in the waveguide resonator. This frequency is determined by a process of modulating and demodulating the beam with a substantially sinusoidal waveform. As such the gyro need not actively switch the laser between the resonant frequencies of both of the directions of propagation in the waveguide resonator. This results in a gyro that has less noise, improved signal quality, and reduced complexity and cost of fabrication.

A ring-type laser including a traveling wave cavity which incorporates at least first and second straight cavity sections and at least one curved cavity section. Corresponding first ends of the straight cavity sections are interconnected at a first light-emitting facet, and second ends of the straight sections are interconnected by the curved waveguide. Additional curved and straight sections can be linked to provide various ring configurations.

An optical sensor system for providing an output signal in response to a sensed parameter is disclosed. The sensor system comprises an optical signal source generating an input signal, a sensing element in optical communication with the optical signal source and a detector in optical communication with the sensing element. The sensing element comprises at least two resonant cavity loops exhibiting a common resonant frequency near at least one frequency of the input signal, at least one of the resonant cavity loops being exposed to an external parameter. The external parameter modifies the resonant frequency of the at least one exposed resonant cavity loop thereby modifying an optical output signal. The detector detects any modification in the output optical signal in response to the sensed parameter.