Abstract: A fiber optical fiber fluid flow measuring device is provided for in vivo determination of blood flow in arteries. The device includes a fiber optical fluid differential pressure measuring device having at least one optical fiber sensor which optical fiber sensor is positioned in the blood flow passage in a restricted flow area. The fiber optical differential pressure fluid sensor is connected to a divided interferometer associated with an opto-electronic demodulator which has an output signal representing the differential pressure in the sensed area. The device also has utility in industrial applications.

Abstract: A single fiber optic optical sensor in one segment of a divided interferometer and a remote demodulation interferometer segment associated therewith.

Abstract: A single mode optical fiber is used to detect electrical currents or magnetic fields from a source to a high degree of accuracy. Phase modulation of an optical beam is used to determine the changes of physical properties of a magnetostrictive material which jackets the fiber or around which the fiber is wound. An electromagnetic field, such as that emanating from a high intensity field wire, is measured by the device which acts as a current transformer and meters peak-to-peak electric currents of approximately 10,000 amperes or more with accuracy exceeding 0.1%. The invention structure of the device provides advantages such as operation safety, EMI immune leads, low cost, light weight, and dielectric construction among others.

Abstract: A single fiber optical fiber temperature measuring device is provided for in vivo determination of temperature at a plurality of spaced points. The device includes a fiber optical temperature sensing device having at least first and second optical fiber sensors which optical fiber sensors are positioned at the measurement sites and at least two fiber optical sensors are connected to a divided interferometer associated with an opto-electronic demodulator which has an output signal representing the temperature at the sensed sites. The device also has utility in industrial or chemical temperature sensing applications.

Abstract: A force measuring device generally comprising a hollow, three-dimensional container defining interiorly thereof at least one chamber is disclosed. The device includes at least a pair of optical fiber coils with the length of the optical fiber on each of the coils being substantially equal. The pair of coils are mounted on opposite sides of a wall of the hollow container and there are means within the container normally exerting a force on the coil mounted within the container. The system also includes an optical interferometer having a pair of legs with means connecting each of the pair of coils in a leg of the interferometer. Radiant energy emitting means are provided for directing radiant energy into the legs of the interferometer and through the pair of coils and radiant energy detecting means are connected to the interferometer.

Abstract: The invention relates to a technique for detecting electric fields by modulating the phase of an optical beam. A length of optical fiber is jacketed with or attached to piezoelectric material that is poled perpendicular to the length of the fiber. An electric field is applied across the piezoelectric element, i.e. in the direction of poling, resulting in a change in the element thickness and a change in the axial dimension, which, in turn, changes the length of the optical fiber. The change in fiber length is accompanied by a smaller change in the refractive index of the fiber. The result is a shift in the optical phase.

Abstract: A fiber optic musical instrument provides a design in which the musical notes and characteristic instrument sounds normally sensed by electro-mechanical devices such as magnetic pickups and acoustic transducers are generated by the modulation of light within optical fibers and are optically transmitted to amplifying devices without the need for externally mounted sensing devices.