Abstract: Described is a fiber optic cable useful as a sensor for the detection of water or hydrocarbons. The fiber optic cable has sensor portions in line with fiber optic portions; the refractive index of the sensor portion changes when the sensor portion is placed in contact with water or hydrocarbons.

Abstract: The present disclosure relates to optical fiber-based devices, and more particularly to light-absorbing optical fiber-based systems and methods.

Abstract: The present invention relates to a sensor using a tilted fiber grating to detect physical manifestations occurring in a medium. Such physical manifestations induce measurable changes in the optical property of the tilted fiber grating. The sensor comprises a sensing surface which is to be exposed to the medium, an optical pathway and a tilted grating in the optical pathway. The grating is responsive to electromagnetic radiation propagating in the optical pathway to generate a response conveying information on the physical manifestation.

Abstract: The present invention relates to a sensor using a tilted fiber grating to detect physical manifestations occurring in a medium. Such physical manifestations induce measurable changes in the optical property of the tilted fiber grating. The sensor comprises a sensing surface which is to be exposed to the medium, an optical pathway and a tilted grating in the optical pathway. The grating is responsive to electromagnetic radiation propagating in the optical pathway to generate a response conveying information on the physical manifestation.

Abstract: The present invention relates to a sensor using a tilted fiber grating to detect physical manifestations occurring in a medium. Such physical manifestations induce measurable changes in the optical property of the tilted fiber grating. The sensor comprises a sensing surface which is to be exposed to the medium, an optical pathway and a tilted grating in the optical pathway. The grating is responsive to electromagnetic radiation propagating in the optical pathway to generate a response conveying information on the physical manifestation.

Abstract: The present invention provides, in addition to other things, methods, systems, and apparatuses that involve the use of an optical fiber with grating and particulate coating that enables simultaneous heating; optical detection; and optionally temperature measurement. Methods, systems, and apparatuses of the present invention may be used in many applications including isothermal and/or thermal cycling reactions. In certain embodiments, the present invention provides methods, systems, and apparatuses for use in detecting, quantifying and/or identifying one or more known or unknown analytes in a sample.

Abstract: The present invention relates to a sensor using a tilted fiber grating to detect physical manifestations occurring in a medium. Such physical manifestations induce measurable changes in the optical property of the tilted fiber grating. The sensor comprises a sensing surface which is to be exposed to the medium, an optical pathway and a tilted grating in the optical pathway. The grating is responsive to electromagnetic radiation propagating in the optical pathway to generate a response conveying information on the physical manifestation.

Abstract: The present invention relates to a sensor using a tilted fiber grating to detect physical manifestations occurring in a medium. Such physical manifestations induce measurable changes in the optical property of the tilted fiber grating. The sensor comprises a sensing surface which is to be exposed to the medium, an optical pathway and a tilted grating in the optical pathway. The grating is responsive to electromagnetic radiation propagating in the optical pathway to generate a response conveying information on the physical manifestation.

Abstract: An optical device includes an optical fiber having a core including multicomponent phosphate glasses, and a cladding surrounding the core, and a first fiber Bragg grating formed in a first portion of the core of the optical fiber and having an index modulation amplitude greater than 2×10?5.

Abstract: The present invention relates to a sensor using a tilted fiber grating to detect physical manifestations occurring in a medium. Such physical manifestations induce measurable changes in the optical property of the tilted fiber grating. The sensor comprises a sensing surface which is to be exposed to the medium, an optical pathway and a tilted grating in the optical pathway. The grating is responsive to electromagnetic radiation propagating in the optical pathway to generate a response conveying information on the physical manifestation.

Abstract: An optical device includes an optical fiber having a core including multicomponent phosphate glasses, and a cladding surrounding the core, and a first fiber Bragg grating formed in a first portion of the core of the optical fiber and having an index modulation amplitude greater than 2×10?5.

Abstract: An assembly for providing thermal compensation to a fiber optical device is described. The optical fiber device is secured in a support structure made of a material having a negative coefficient of thermal expansion. The securing means located at on end of the support structure is made of a material having a positive coefficient of thermal expansion. The securing means is also adjustable lengthwise so as to provide longitudinal adjustment to the tension on the optical fiber device. By selecting the appropriate materials and dimensions the assembly can exactly compensate for the thermal dependency of the optical device with an overall length much smaller than assemblies based on materials with dissimilar positive CTEs.

Abstract: An assembly for providing thermal compensation to a fiber optical device is described. The optical fiber device is secured in a support structure made of a material having a negative coefficient of thermal expansion. The securing means located at on end of the support structure is made of a material having a positive coefficient of thermal expansion. The securing means is also adjustable lengthwise so as to provide longitudinal adjustment to the tension on the optical fiber device. By selecting the appropriate materials and dimensions the assembly can exactly compensate for the thermal dependency of the optical device with an overall length much smaller than assemblies based on materials with dissimilar positive CTEs.

Abstract: An assembly for providing thermal compensation to a fiber optical device is described. The optical fiber device is secured in a support structure made of a material having a negative coefficient of thermal expansion. The securing means located at on end of the support structure is made of a material having a positive coefficient of thermal expansion. The securing means is also adjustable lengthwise so as to provide longitudinal adjustment to the tension on the optical fiber device. By selecting the appropriate materials and dimensions the assembly can exactly compensate for the thermal dependency of the optical device with an overall length much smaller than assemblies based on materials with dissimilar positive CTEs.

Abstract: A system and method of compensating for the thermal dependence of fiber optic devices, such as Bragg gratings, are described. Fiber optic devices such as Bragg filters are subject to change as a function of temperature. If the device contains a grating which is written to perform a function at a specific central wavelength, a slight increase in length of the device and hence an increase in the grating spacing due to an increase in temperature will change the central wavelength. The present invention provides a two-part substrate structure with each part having a different coefficient of thermal expansion. The fiber optic device is attached under tension to one part of the substrate that has, for example, a low coefficient of thermal expansion. This part has a channel on the side opposite to the fiber optic device and a second part of the substrate structure is held within the channel. The second part has a high coefficient of thermal expansion.

Abstract: A method is disclosed wherein optical structures such as Bragg gratings can be written into planar waveguides disposed on a substrate. By employing the method of this invention, a polarization insensitive device can be made. Such relatively thin planar waveguides disposed on a substrate are inherently polarization sensitive and the structure itself is birefringent. By writing structures in the waveguides or by simply writing a refractive index change in the waveguide by limiting the beam width at the waveguide layer to less than or equal to the thickness of the waveguiding layers on the substrate, in combination with conventional wider beam writing techniques, polarization sensitivity can be lessened or obviated.

Abstract: A method is disclosed wherein optical structures such as Bragg gratings can be written into planar waveguides disposed on a substrate. By employing the method of this invention, a polarization insensitive device can be made. Such relatively thin planar waveguides disposed on a substrate are inherently polarization sensitive and the structure itself is birefringent. By writing structures in the waveguides or by simply writing a refractive index change in the waveguide by limiting the beam width at the waveguide layer to less than or equal to the thickness of the waveguiding layers on the substrate, in combination with conventional wider beam writing techniques, polarization sensitivity can be lessened or obviated.

Abstract: A method is disclosed wherein optical structures such as Bragg gratings can be written into planar waveguides disposed on a substrate. By employing the method of this invention, a polarization insensitive device can be made. Such relatively thin planar waveguides disposed on a substrate are inherently polarization sensitive and the structure itself is birefringent. By writing structures in the waveguides or by simply writing a refractive index change in the waveguide by limiting the beam width at the waveguide layer to less than or equal to the thickness of the waveguiding layers on the substrate, in combination with conventional wider beam writing techniques, polarization sensitivity can be lessened or obviated.

Abstract: A method of fabricating a strongly photosensitive optical waveguide is comprised of locally heating at least a portion of a weakly photosensitive optical waveguide for a period of time sufficient to increase the density of defects associated with photosensitivity in the heated portion of the waveguide core.