Abstract: Improved fiber optics pressure sensor transducers utilizing fiber optics in an interferometer sensing element. Included is a bellows-type pressure-to-movement converter that translates sensed pressure into linear displacement. That displacement is mechanically coupled to, and thereby varies the length of one leg of a fiber optics interferometer as a function of pressure. A temperature compensator is attached to the sensing or reference optical fiber of the interferometer. The temperature compensator causes corrective changes in the length of that optical fiber to which it is attached, thereby compensating for opposing temperature effects on other parts of the interferometer. Threaded studs attached to flexible stress reducers which are in turn coupled to optical fiber grippers provide means for adjusting interferometer optical fiber pre-tension and rotation to optimize polarization.

Abstract: An attachment structure is described that provides means for holding and for applying tensile force to an optical fiber clamped therein. Attachment to an optical fiber is accomplished by stripping the buffer layer(s) from a portion of the fiber and casting a thermosetting polymer encapsulating and compressing member thereon at elevated temperature so that, at lower than the polymer curing temperature, the cast polymer encapsulating member is in compression on the bared fiber and on a short portion of its adjacent buffer layer(s). A tension wire which provides a means for applying external force to the optical fiber has one end inserted axially in the mold for incorporation into the cast encapsulating member. The wire is also placed under compression at temperatures below that of the curing temperature of the polymer. To maintain compression over temperature elevated temperatures, a restrictive cylindrical coil spring is directly engaged around the encapsulating member.

Abstract: A sensing system having a wideband optical source for providing optical illumination having a bandwidth of at least 25 nanometers, and an optical fiber cable for transmitting the optical illumination to a remote location. A transducer responsive to the transmitted optical illumination amplitude modulates the transmitted optical illumination as a function of a monitored physical parameter (for example, pressure or temperature) to provide an amplitude modulated optical illumination having generally sinusoidally varying nulls across the spectrum thereof, the frequency of the nulls varying across the spectrum of the modulated optical illumination and being a function of the monitored physical parameter. The fiber optic cable (or another fiber optic cable, depending on the transducer implementation) transmits the modulated optical illumination to an optical spectral analyzer which provides a spectrally dispersed optical signal indicative of the spectral content and amplitudes of the modulated optical illumination.