Abstract: In accordance with one aspect of the invention, a ring laser configuration having a polarizer, and whose cavity loop has substantially no net dispersion, permitting mode locked pulsing of high intensity and large bandwidth. In accordance with another aspect of the invention, a system using this laser to interrogate a plurality of arrays of Bragg gratings by use of both time and wavelength division multiplexing, increasing the total number of interrogatable gratings. In accordance with a third aspect of the invention, a system for interrogating one or more fiber Bragg gratings separated from the optical source by a dispersive optical fiber. As such a grating distends responsive to some measurand, its reflection frequency changes, and the traversal time of the reflection over the dispersive fiber changes, permitting inference of the measurand.

Abstract: An apparatus for the determination of the wavelength and the detection of velength shifts in wavelength-encoded fiber sensors, such as Bragg grating sensors. The apparatus is implemented in fiber and uses a pair of tuned fiber gratings to provide a filter type function that tracks the wavelength component of a signal from a wavelength-encoded sensor.