Integrated optical devices which utilize a magnetostrictively, electrostrictively or photostrictively induced stress to alter the optical properties of one or more waveguides in the device are disclosed. The integrated optical devices consist of at least one pair of optical waveguides preferably fabricated in a cladding material formed on a substrate. A stress applying material, which may be a magnetostrictive, electrostrictive or photostrictive material, is affixed to the upper surface of the cladding material near at least one of the optical waveguides. When the appropriate magnetic, electric or photonic field is applied to the stress applying material, a dimensional change tends to be induced in the stress applying material. The constrained state of the stress applying material, however, caused by its adhesion to the cladding material, causes regions of tensile and compressive stress, as well as any associated strains, to be created in the integrated optical device. By positioning one or more optical waveguides in a region of the device which will be subjected to a tensile or compressive stress, the optical properties of the stressed waveguide may be varied to achieve switching and modulation. Latchable integrated optical devices are achieved by utilizing a controlled induced stress to "tune" one or more waveguides in an integrated optical device to a desired refractive index or birefringence, which will be retained after the field is removed.

Integrated optical devices utilizing magnetostrictively, electrostrictively or photostrictively induced stress

An optical transducer with an optical waveguide having two paths for the propagation of light is deformed in response to acoustical pressure variations or other parameters to be sensed to modulate the amplitude of the light propagated along the two paths in opposite polarities. The light outputs of the two paths are sensed by photodetectors and applied to an electrical differencing circuit. The mean values of the photodetector outputs are balanced as by mechanically providing a predetermined bias deformation of the fiber, or by electrically matching outputs of the detectors such that, on the average, the output of the differencing circuit is zero. Dynamic deformation of the fiber in the transducer results in unbalanced outputs of the photodetectors which unbalance is sensed by the differencing circuit. This differential detection method minimizes optical and mechanical sources of noise in the light source and waveguide and leads to increased signal-to-noise and enhanced dynamic range of the transducer.

Optical sensor system

The frequency of an optical signal output from an optical source is controlled by dividing a signal output from the source into two signal portions each of which is guided along its own optical path. The signal portions are combined to form two optical beams each including components of the two signal portions and having intensities dependent on an adjusted frequency of the two beams.

Apparatus and method for optical signal source stabilization

Radiant energy is caused to modulate in phase and frequency in a single mode optical fiber by means of a relatively movable, spatially periodic perturbation

Method and apparatus for radiant energy modulation in optical fibers

The apparatus according to the invention is all-fiber optic device that produces an output indicative of the gradient of an acoustic wave in water The device comprises a neutrally buoyant body having a relatively rigid outer case When it is submerged in water, the motion of the case is the same as that of a water particle in the same vicinity A fiber optic linear accelerometer produces a signal proportional to the component of acceleration

Fiber optic gradient hydrophone and method of using same

Light is modulated in an optic fiber by applying compression across diameters of the fiber angularly displaced from one another and axially displaced from one another along the fiber. Independent phase modulation is achieved by varying the compression applied across the diameters equally and with the same direction. Independent amplitude modulation is achieved by varying the compression applied across the diameters equally and with opposite polarity directions.

Luther W Smith

Papers

Light modulation in optic fiber