Abstract: An interrogator for a plurality of sensor fiber optic gratings. The interrogator includes an optical source for providing signals to the plurality of sensor fiber optic gratings. At least one optical filter converts optical signals, returned from the plurality of sensor fiber optic gratings, from (a) changes in peak reflection wavelength to (b) changes in intensity. At least one optical receiver receives the converted optical signals from the at least one optical filter.

Abstract: An interrogator for a plurality of sensor fiber optic gratings. The interrogator includes a broadband optical source; at least one beam splitter directing output of the optical source to the sensor fiber optic gratings; at least one linear filter for converting changes in peak reflection wavelength to changes in intensity; at least one optical receiver; and at least one amplifier associated with each optical receiver. The interrogator also includes an analog integrator following the at least one amplifier.

Abstract: An optical detection system. The optical detection system includes a host node having (a) an optical source for generating optical signals, and (b) an optical receiver. The optical detection system also includes a plurality of fiber optic sensors for converting at least one of vibrational and acoustical energy to optical intensity information, each of the fiber optic sensors having: (1) at least one length of optical fiber configured to sense at least one of vibrational and acoustical energy; (2) a reflector at an end of the at least one length of optical fiber; and (3) a field node for receiving optical signals from the host node, the field node transmitting optical signals along the at least one length of optical fiber, receiving optical signals back from the at least one length of optical fiber, and transmitting optical signals to the optical receiver of the host node.

Abstract: A fiber optic security system is provided. The fiber optic security system includes at least one length of fiber optic cable affixed to at least one item to be monitored using the fiber optic security system. The fiber optic security system also includes at least one local control node, the at least one local control node including at least one light source for generating and transmitting light through the at least one length of fiber optic cable, and the at least one local control node monitoring a status of the light. The fiber optic security system also includes a remote control unit for receiving information from the at least one local control node regarding the status of the light.

Abstract: A personnel monitoring system. The personnel monitoring system includes a host node having an optical source for generating optical signals, and an optical receiver. The personnel monitoring system also includes a plurality of fiber optic sensors for converting at least one of vibrational and acoustical energy to optical intensity information, each of the fiber optic sensors having: (1) at least one length of optical fiber configured to sense at least one of vibrational and acoustical energy; (2) a reflector at an end of the at least one length of optical fiber; and (3) a field node for receiving optical signals from the host node, the field node transmitting optical signals along the at least one length of optical fiber, receiving optical signals back from the at least one length of optical fiber, and transmitting optical signals to the optical receiver of the host node.

Abstract: An optical detection system for monitoring a pipeline. The optical detection system includes a host node in the vicinity of or remote from, a pipeline to be monitored. The optical detection system includes (a) an optical source for generating optical signals, and (b) an optical receiver.

Abstract: An interrogator for a plurality of sensor fiber optic gratings. The interrogator includes a broadband optical source; at least one beam splitter directing output of the optical source to the sensor fiber optic gratings; at least one linear filter for converting changes in peak reflection wavelength to changes in intensity; at least one optical receiver; and at least one amplifier associated with each optical receiver. The interrogator also includes, alternatively, a driver/modulator for the optical source providing on/off pulses; an analog integrator following the at least one amplifier; or a mechanism compensating for masking of one sensor fiber optic grating by another.

Abstract: A fiber optic microseismic sensing system is provided. The system includes a plurality of nodes, each of the nodes including a surface portion, an underground portion, and an optical cable extending between the surface portion and the underground portion. The surface portion includes (1) an optical source for transmitting an optical signal along the optical cable to the underground portion, and (2) an optical receiver for receiving a return optical signal propagating along the optical cable from the underground portion. The underground portion includes at least one transducer, each of the at least one transducer including (1) a fixed portion configured to be secured to a body of interest, (2) a moveable portion having a range of motion with respect to the fixed portion, (3) a spring positioned between the fixed portion and the moveable portion, and (4) a mass engaged with the moveable portion.

Abstract: A fiber optic transducer is provided. The fiber optic transducer includes a fixed portion configured to be secured to a body of interest, a moveable portion having a range of motion with respect to the fixed portion, a spring positioned between the fixed portion and the moveable portion, and a length of fiber wound between the fixed portion and the moveable portion. The length of fiber spans the spring. The fiber optic transducer also includes a mass engaged with the moveable portion. In one disclosed aspect of the transducer, the mass envelopes the moveable portion.

Abstract: An interrogator for a plurality of sensor fiber optic gratings. The interrogator includes a broadband optical source; at least one beam splitter directing output of the optical source to the sensor fiber optic gratings; at least one linear filter for converting changes in peak reflection wavelength to changes in intensity; at least one optical receiver; and at least one amplifier associated with each optical receiver. The interrogator also includes, alternatively, a driver/modulator for the optical source providing on/off pulses; an analog integrator following the at least one amplifier; or a mechanism compensating for masking of one sensor fiber optic grating by another.

Abstract: An interrogator for a plurality of sensor fiber optic gratings. The interrogator includes a broadband optical source; at least one beam splitter directing output of the optical source to the sensor fiber optic gratings; at least one linear filter for converting changes in peak reflection wavelength to changes in intensity; at least one optical receiver; and at least one amplifier associated with each optical receiver. The interrogator also includes, alternatively, a driver/modulator for the optical source providing on/off pulses; an analog integrator following the at least one amplifier; or a mechanism compensating for masking of one sensor fiber optic grating by another.

Abstract: An interrogator for a plurality of sensor fiber optic gratings. The interrogator includes a broadband optical source; at least one beam splitter directing output of the optical source to the sensor fiber optic gratings; at least one linear filter for converting changes in peak reflection wavelength to changes in intensity; at least one optical receiver; and at least one amplifier associated with each optical receiver. The interrogator also includes, alternatively, a driver/modulator for the optical source providing on/off pulses; an analog integrator following the at least one amplifier; or a mechanism compensating for masking of one sensor fiber optic grating by another.

Abstract: A fiber optic security system is provided. The fiber optic security system includes at least one length of fiber optic cable affixed to at least one item to be monitored using the fiber optic security system. The fiber optic security system also includes at least one local control node, the at least one local control node including at least one light source for generating and transmitting light through the at least one length of fiber optic cable, and the at least one local control node monitoring a status of the light. The fiber optic security system also includes a remote control unit for receiving information from the at least one local control node regarding the status of the light.

Abstract: An interrogator for a plurality of sensor fiber optic gratings. The interrogator includes a broadband optical source; at least one beam splitter directing output of the optical source to the sensor fiber optic gratings; at least one linear filter for converting changes in peak reflection wavelength to changes in intensity; at least one optical receiver; at least one amplifier associated with each optical receiver; and an active closed-loop circuit following the at least one amplifier to provide bias voltage stabilization.

Abstract: A fiber optic interrogator includes a broadband optical source, at least one beam splitter directing output of the optical source to an array of fiber optic gratings, at least one linear transmission or reflection filter, at least one optical receiver and at least one amplifier associated with each receiver. In one aspect of the invention, a linear transmission filter is used to convert the change in center wavelength of a grating reflectivity spectrum to a change in intensity, which is proportional to the change in the grating central wavelength. In another aspect of the invention, a pair of opposite-sloped linear transmission filters are utilized to normalize the received and filtered reflections with respect to total optical power. In another aspect of the invention, the optical source is pulsed, and return pulses from each fiber optic grating to be measured are sampled by the interrogator at different times.

Abstract: A fiber optic interrogator includes a broadband optical source, at least one beam splitter directing output of the optical source to an array of fiber optic gratings, at least one linear transmission or reflection filter, at least one optical receiver and at least one amplifier associated with each receiver. In one aspect of the invention, a pair of opposite-sloped linear transmission filters are utilized to normalize the received and filtered reflections with respect to total optical power.

Abstract: A fiber optic interrogator includes a broadband optical source, at least one beam splitter directing output of the optical source to an array of fiber optic gratings, at least one linear transmission or reflection filter, at least one optical receiver and at least one amplifier associated with each receiver. In one aspect of the invention, a linear transmission filter is used to convert the change in center wavelength of a grating reflectivity spectrum to a change in intensity, which is proportional to the change in the grating central wavelength. In another aspect of the invention, a pair of opposite-sloped linear transmission filters are utilized to normalize the received and filtered reflections with respect to total optical power. In another aspect of the invention, the optical source is pulsed, and return pulses from each fiber optic grating to be measured are sampled by the interrogator at different times.