Abstract: Fuel injectors (10) for internal combustion engines are modified and equipped with fiber optic fuel pressure sensors (12) and fiber optic combustion pressure sensors (14). The combustion pressure sensors (14) are located in separate channels (26) formed in the fuel injectors with the lower portion (22) of the channels leading to the combustion chambers. Above the combustion pressure sensors (14) are fiber optic leads (24). In the preferred embodiments the sensors (46) are equipped with diaphragms (40) of novel shape (48) and employ multiple pairs of fibers (86, 88), temperature sensitive components (72, 74, 126) and novel compensation and status monitoring circuits (FIGS. 6, 9, 10, 14, 15, 18).

Abstract: Compensation techniques for high temperature fiber-optic pressure sensors are aimed at correcting for the sensor sensitivity and offset dependence on temperature. By using materials of different thermal expansion coefficients for the sensor diaphragm, housing, ferrule and fiber-bonding compound and by optimizing the length of such parts, the relative distance of the fiber tip with respect to the sensing diaphragm changes in a manner that reduces sensor sensitivity and/or offset dependence on temperature. In the first embodiment, the distance change results from controlled fiber movement within the ferrule and is used to reduce the temperature sensitivity of dynamic sensors. In the second embodiment, an optimum selection of the diaphragm, housing, ferrule and bonding compound materials yields a stable fiber position within the ferrule but, instead, a well defined ferrule movement with respect to the diaphragm in response to temperature changes.

Abstract: A method and apparatus for a high temperature corrosion resistant composition. The composition is formed into a bulb shield for a vehicle, including automobiles and motorcycles. An alloy composition may be used to stamp a bulb shield. The bulb shield may comprise a cup portion and a connector. Either the cup portion, the connector, or both may comprise an Inconel® alloy composition. The bulb shield may be positioned in front of a headlight bulb to steer light in a desired direction. The bulb shield may be electropolished to provide a decorative attribute to the lamp. The bulb shield may be exposed to high temperatures from the headlight bulb. The Inconel® composition resists deterioration and discoloration of the bulb shield due to the high temperatures. The Inconel® 600 composition also improves the durability of the bulb shield.

Abstract: A method and apparatus for a high temperature corrosion resistant composition. The composition is formed into a bulb shield for a vehicle, including automobiles and motorcycles. An alloy composition may be used to stamp a bulb shield. The bulb shield may comprise a cup portion and a connector. Either the cup portion, the connector, or both may comprise an Inconel® alloy composition. The bulb shield may be positioned in front of a headlight bulb to steer light in a desired direction. The bulb shield may be electropolished to provide a decorative attribute to the lamp. The bulb shield may be exposed to high temperatures from the headlight bulb. The Inconel® composition resists deterioration and discoloration of the bulb shield due to the high temperatures. The Inconel® 600 composition also improves the durability of the bulb shield.

Abstract: Fuel injectors (10) for internal combustion engines are modified and equipped with fiber optic fuel pressure sensors (12) and fiber optic combustion pressure sensors (14). The combustion pressure sensors (14) are located in separate channels (26) formed in the fuel injectors with the lower portion (22) of the channels leading to the combustion chambers. Above the combustion pressure sensors (14) are fiber optic leads (24). In the preferred embodiments the sensors (46) are equipped with diaphragms (40) of novel shape (48) and employ multiple pairs of fibers (86, 88), temperature sensitive components (72, 74, 126) and novel compensation and status monitoring circuits (FIGS. 6, 9, 10, 14, 15, 18).

Abstract: Compensation and health monitoring techniques and devices for fiber optic intensity modulated sensors provide automatic adjustment of light intensity in order to maintain continuous calibration of the fiber optic sensors in the presence of undesirable environmental or handling conditions. These undesirable conditions may arise from such factors as fiber bending, optical connector mechanical and thermal instabilities, extreme temperatures at sensors, and changes in optical coupling between optical sources (e.g., light emitting diodes) and detectors (e.g., PIN photodiodes) and the optical fibers. Through light intensity normalization, the new techniques enable a continuous calibrated sensor output and sensor health monitoring by continuous or intermittent observation of the light emitting diode current.

Abstract: An acousto-optical seismic sensor array includes a distributed set of optical-fiber sensing coils. A light pulse is launched through the sensing coils in serial order. The light pulse is cumulatively data-modulated by the respective sensing coils and is returned as a time-division multiplexed pulse train. The pulse train is split into a first pulse train and a retarded second pulse train. The retardation time equals the travel-time delay of a light pulse between sensors. The retarded pulse train is compared with the first pulse train to determine the phase shift therebetween for consecutive pulses. The phase shift is an analog of the quantity being sensed.

Abstract: An optical fiber rotary measurement sensor for flow meters and other mechanical devices incorporates a housing having an encoder disc mounted by a drive shaft for driven rotation, the drive shaft being driven by a flow meter mechanism or by any other mechanical device. The encoder forms evenly spaced light absorbing and light reflecting areas at the outer periphery thereof and optical fibers are positioned to project light onto and receive reflected light from the outer periphery of the encoder disc. An opto-electronic signal processor receives reflected light pulses from the reflective surface areas and translates the light pulses into electrical pulses. The electrical pulses are in turn input to electronic display circuitry for providing a digital, analog or other suitable display representative of the rotation of the encoder disc and thus representative of rotary output movement of the flow meter or other mechanical device.

Abstract: The expanded-beam fiber, fiber-optic connector assembly includes a body having a longitudinal bore for receiving an aligning sleeve therein which has an axial hole for receiving a strand of optical fiber. The optical fiber may be surrounded by a stress member which is firmly anchored by a crimping sleeve to the exterior of the body. The optical fiber extending through the aligning sleeve is cleaved to within 0.020 inch of the end of the sleeve that slideably receives a ferrule containing a self focusing microlens in one end. The aligning sleeve mates with the ferrule such that the end of the optical fiber is axially aligned and in contact with the microlens. Two such connectors may be coupled together by an aligning ferrule such that the microlenses of each are no more than one quarter of an inch apart.

Abstract: The invention is an optical fiber sensor system in which an optical source, such as a laser diode, emits a pulse of optical energy which is transmitted in an optical path through an optical energy modulator. A partial reflector, included in the optical path before the optical modulator, reflects a portion of the optical energy of the pulse. The optical path terminates in an optical reflector, where the pulse is reflected back through the optical modulator to the partial reflector. The optical energy reflected by the partial reflector and the terminating reflector travels along the same optical path from the partial reflector to a photodetector and demodulator, where the magnitude of the parameter modulating the light modulator is determined from the relative magnitude of the energy reflected from the partial reflector and the terminating reflector.

Abstract: A unitary optical-fiber connector assembly accepts a plurality of input channels and, by means of a common transfer lens of the graded-index type, transfers the input-channel data to a corresponding plurality of optical-fiber output channels.

Abstract: An optical sound source signature transducer system for use in marine seismic exploration in which coherent radiation from a laser is coupled to unequal length optical paths exposed to modulation by the acoustic energy wave generated by the sound source. The reflected beams from the paths are crosscoupled to generate interference fringes in two output beams out of phase with each other. The fringes in one output beam are counted in an up/down counter to determine the magnitude of the pressure as a function of time. The direction of the pressure change is determined by examination of the phase relationship between the fringes in the output beams. Peaks and valleys in the pressure are detected as phase reversals between the fringes in the output beams be detecting the beginning and end of a fringe in one beam without detecting the beginning or end of a fringe in the other beam therebetween.