Abstract: A fiber optic sensor system includes a plurality m of sensor segments, each sensor segment further comprising a plurality n of sensor gratings for making measurements. Each sensor grating of the sensor segment operates within a unique wavelength channel, such that a plurality m of sensor segments have m sensors in each wavelength channel, and n wavelength channels, for a total of m*n sensors. A broadband optical source is gated for a duration of time which enables all of the sensors on a sensor segment to reflect optical energy corresponding to their measurement, but not long enough to receive reflected optical energy from more than one sensor on a single wavelenghth channel. In this manner, n wavelength channels of measurement can be time-multiplexed to measure m*n sensors.

Abstract: Waveguide sensors having a side-polished coupling port at the waveguide cladding to sense a material based on material-specific optical attenuation by evanescent coupling at the coupling port.

Abstract: Fiber sensors formed on side-polished fiber coupling ports based on evanescent coupling. Such sensors may be configured to measure various materials and may be used to form multi-phase sensing devices.

Abstract: Fiber sensors formed on side-polished fiber coupling ports based on evanescent coupling are described. Such sensors may be configured to measure various materials and may be used to form multi-phase sensing devices. A Bragg grating may be implemented in such sensors to form reflective fiber sensors.

Abstract: A fiber optic sensor comprises two independent fibers having Bragg gratings which are coupled to commutating broadband optical sources through splitters and wavelength discriminators. The ratio of detected optical energy in each of two detectors examining the wave intensity returned to a wavelength discriminator coupled with the characteristic of the wavelength discriminator determines the wavelength returned by the grating. In another embodiment, tunable filters are utilized to detect minimum returned wave energy to extract a sensor wavelength Reference to the original grating wavelength indicates the application of either temperature or strain to the grating. In another embodiment, a plurality of Bragg grating sensor elements is coupled to sources and controllers wherein a dimensional change in a fiber having a Bragg grating is detected using a measurement system comprising broad-band sources, optical power splitters, a high-sensitivity wavelength discriminator, optical detectors, and a controller.

Abstract: A fiber optic sensor comprises two independent fibers having Bragg gratings which are coupled to commutating broadband optical sources through splitters and wavelength discriminators. The ratio of detected optical energy in each of two detectors examining the wave intensity returned to a wavelength discriminator coupled with the characteristic of the wavelength discriminator determines the wavelength returned by the grating. In another embodiment, tunable filters are utilized to detect minimum returned wave energy to extract a sensor wavelength Reference to the original grating wavelength indicates the application of either temperature or strain to the grating. In another embodiment, a plurality of Bragg grating sensor elements is coupled to sources and controllers wherein a dimensional change in a fiber having a Bragg grating is detected using a measurement system comprising broad-band sources, optical power splitters, a high-sensitivity wavelength discriminator, optical detectors, and a controller.

Abstract: A fiber optic sensor comprises two independent fibers having Bragg gratings which are coupled to commutating broadband optical sources through splitters and wavelength discriminators. The ratio of detected optical energy in each of two detectors examining the wave intensity returned to a wavelength discriminator coupled with the characteristic of the wavelength discriminator determines the wavelength returned by the grating. In another embodiment, tunable filters are utilized to detect minimum returned wave energy to extract a sensor wavelength Reference to the original grating wavelength indicates the application of either temperature or strain to the grating. In another embodiment, a plurality of Bragg grating sensor elements is coupled to sources and controllers wherein a dimensional change in a fiber having a Bragg grating is detected using a measurement system comprising broad-band sources, optical power splitters, a high-sensitivity wavelength discriminator, optical detectors, and a controller.

Abstract: A fiber optic sensor comprises two independent fibers having Bragg gratings which are coupled to commutating broadband optical sources through splitters and wavelength discriminators. The ratio of detected optical energy in each of two detectors examining the wave intensity returned to a wavelength discriminator coupled with the characteristic of the wavelength discriminator determines the wavelength returned by the grating. In another embodiment, tunable filters are utilized to detect minimum returned wave energy to extract a sensor wavelength. Reference to the original grating wavelength indicates the application of either temperature or strain to the grating. In another embodiment, a plurality of Bragg grating sensor elements is coupled to sources and controllers wherein a dimensional change in a fiber having a Bragg grating is detected using a measurement system comprising broad-band sources, optical power splitters, a high-sensitivity wavelength discriminator, optical detectors, and a controller.