Abstract: Optical device for distributed sensing of a measurand and/or changes thereof where the spectral transmission and reflection characteristics of the device depend upon the measurand. A passive sensing section have at least one Bragg grating sensing structure in a waveguide. The Bragg grating sensing structure comprises at least two superimposed or partly overlapping Bragg subgratings with at least two different Bragg wavelengths. At least two of the said Bragg subgratings comprise a phase-shift. The Bragg subgratings have their phase shifts spatially separated from each other along the waveguide sensing section. The sensing section can be made active by at least partly doping it with rare earth ions and forming a laser medium, or an active component. Examples of using the passive as well as the active sensing sections in optical distributed sensors are described.

Abstract: A Bragg Grating optical waveguide laser source comprising at least one Bragg grating in a rare earth doped waveguide and an optical pump source coupled to said doped waveguide, said Bragg gratings having at least two different peak reflection wavelengths and at least one of said Bragg gratings comprising a phase-shift and a phase-shift actuator being coupled to the phase-shift for controlled application of changes in the phase-shift thus activating or deactivating the corresponding Bragg grating waveguide laser.

Abstract: A Bragg Grating optical waveguide laser source comprising at least one Bragg grating in a rare earth doped waveguide and an optical pump source coupled to said doped waveguide, said Bragg gratings having at least two different peak reflection wavelengths and at least one of said Bragg gratings comprising a phase-shift and a phase-shift actuator being coupled to the phase-shift for controlled application of changes in the phase-shift thus activating or deactivating the corresponding Bragg grating waveguide laser.