Abstract: The present invention is for a fiber optic flow cell. The flow cell comprises a substrate having at least one sample channel and at least one optical fiber channel holder. At least one optical fiber is disposed within each optical fiber channel holder. Each optical fiber has at least one grating wherein each grating is in contact with each sample channel, defining a sensing area. At least one sample port is positioned in an operable relationship to at least one sample channel. Alternatively, at least one sample outlet is positioned in an operable relationship to at least one sample channel. The flow cell may be of a modular design providing a flow cell kit that contains pieces that may be assembled to form custom-made flow cells. The flow cell is used for conducting measurement studies on a sample.

Abstract: Various exemplary embodiments, devices, systems, and methods for sensing moisture are disclosed, including at least one moisture sensor that comprises an optical fiber, a long period grating formed in at least a portion of the optical fiber, and a layer of PEI bonded to the long period grating. One exemplary embodiment comprises a system for measuring humidity, the system comprising an optical fiber moisture sensor having a mono-layer of PEI covalently-bonded to an outer surface of said optical fiber, a processor coupled to said optical fiber moisture sensor, and a moisture indicator coupled to said processor.

Abstract: A fiber-optic method for making simultaneous multiple parameter measurements employs an optical fiber sensor having at least one long period grating disposed therein. An excitation is created in the optical fiber sensor wherein a plurality of evanescent field sensing depths result. At least two long period grating signatures are created. When the optical fiber sensor is exposed to at least one material, changes in the material are identified by simultaneously measuring and comparing shifts in each long period grating signature; correlating the shifts to changes in the material; and solving a series of equations that compare changes in the coupling wavelength for a specific loss band. A reactive coating may be applied to the optical fiber sensor proximate to the long period grating such that changes in the reactive coating as it reacts with the material may also be monitored.

Abstract: A fiber-optic method for making simultaneous multiple parameter measurements employs an optical fiber sensor having at least one long period grating disposed therein. An excitation is created in the optical fiber sensor wherein a plurality of evanescent field sensing depths result. At least two long period grating signatures are created. When the optical fiber sensor is exposed to at least one material, changes in the material are identified by simultaneously measuring and comparing shifts in each long period grating signature; correlating the shifts to changes in the material; and solving a series of equations that compare changes in the coupling wavelength for a specific loss band. A reactive coating may be applied to the optical fiber sensor proximate to the long period grating such that changes in the reactive coating as it reacts with the material may also be monitored.

Abstract: The present invention is for a fiber optic flow cell. The flow cell comprises a substrate having at least one sample channel and at least one optical fiber channel holder. At least one optical fiber is disposed within each optical fiber channel holder. Each optical fiber has at least one grating wherein each grating is in contact with each sample channel, defining a sensing area. At least one sample port is positioned in an operable relationship to at least one sample channel. Alternatively, at least one sample outlet is positioned in an operable relationship to at least one sample channel. The flow cell may be of a modular design providing a flow cell kit that contains pieces that may be assembled to form custom-made flow cells. The flow cell is used for conducting measurement studies on a sample.

Abstract: An extrinsic optical waveguide sensor for making refractive index measurements of an in situ sample is provided. The sensor comprises a holder having at least one sample input region and at least one interferometric region. At least one optical fiber is positioned in the holder, each optical fiber having an endface serving as an input and an output. At least one reflector, each reflector is positioned in the holder in an operable relationship to each optical fiber endface, thus defining each interferometric region.

Abstract: A single-ended long period grating optical device is presented. The single-ended optical device comprises an optical waveguide having at least one core mode and a plurality of cladding modes. At least one long period grating couples light from the core mode to the cladding modes. A reflector is positioned in an operable relationship to the long period grating, and the reflector reflects a signal. A mode stripper is positioned after the long period grating and removes the cladding modes from a transmitted signal and the reflected signal.