Abstract: An optical sensor having at least one long period grating disposed within an optical waveguide is provided. The optical waveguide has a refractive index profile. The long period grating has a plurality of index perturbations spaced apart by a periodic distance .LAMBDA.. The long period grating promotes an excitation of confined propagating broadband light into higher order modes that excite a sensing mechanism. The excitation of confined propagating broadband light is spectrally dependent on the periodic distance of the long period grating and the refractive index profile of the optical waveguide.

Abstract: An optical sensor is provided. The optical sensor comprises an optical waveguide, at least one long period grating disposed within the optical waveguide and a reactive coating positioned in an operable relationship to the long period grating wherein the reactive coating causes the long period grating to produce a wavelength transmission spectrum functionally dependent on a parameter sensed. Such sensors may be used to measure physical, electrical and chemical parameters within a single system.

Abstract: An optical waveguide sensor arrangement for sensing at least one physical parameter is provided. This arrangement comprises an optical waveguide having guided modes, lossy non-guided modes, and a long period grating coupling the guided modes to the lossy non-guided modes wherein the long period grating produces a wavelength transmission spectrum functionally dependent on the physical parameter sensed. A source means provides light to the optical waveguide sensor and an optoelectronic detector, which is positioned in an operable relationship to the optical waveguide sensor, detects light transmitted through the optical waveguide sensor. Lastly, a processing means is attached to the optoelectronic detector for correlating the wavelength transmission spectrum with a numerical value for the physical parameter sensed. The physical parameters sensed by the optical waveguide sensor include: temperature, strain, shape, refractive index and corrosion.