Abstract:
An optical sensor is disclosed in which an aperture is provided in a substrate under at least part of a sensing waveguide structure, so as to reduce thermal coupling between the substrate and the sensing waveguide structure. The optical sensor may be used for sensing temperature of an adjacent gas.
Abstract:
A multilayer polymer film comprising an outer skin layer, an inner seal layer and at least one core layer disposed between the inner and outer skin layer, wherein the outer skin layerscomprises a metallocene-catalyzed ethylene polymer having a density of equal to or greater than about 0.945 g/cc and a melt index equal to or greater than 0.5 g/10 min. A multilayer polymer film comprising a metallocene-catalyzed high-density polyethylene homopolymer skin layer and at least one core layer comprising a high-density polyethylene having a melt index of less than or equal to 2.0 g/10 min. A multilayer polymer film comprising at least a skin layer and a core layer wherein the skin layer comprises a metallocene-catalyzed ethylene polymer provided from a catalyst composition comprising a single metallocene and an activator support.
Abstract:
A fiber Bragg grating cross-wire sensor may be used to independently determine strain and temperature variation. An example fiber Bragg grating cross-wire sensor comprises a first fiber Bragg grating (FBG) that reflects a first percentage, R 1 , of light of a first wavelength, λ 1 , and a second FBG that reflects a second percentage, R2, of light of a second wavelength, λ 2 . The second FBG is positioned orthogonal to the first FBG, and λ 1 is substantially equal to λ 2 , but R 1 is different from R 2 . As the FBG cross- wire sensor experiences a strain and/or a temperature variation, the wavelengths of light reflected by the first FBG and the second FBG will shift from the first and second wavelength, λ 1 and λ 2 , to first and second shifted wavelengths, λ A and λ T , respectively. Based on R 1 R 2 , λ 1 , λ A , and XT, the strain and/or the temperature variation may be independently determined..
Abstract:
The invention relates to an optical waveguide and an optical measurement device, comprising at least one optical waveguide (2), which comprises at least one Fiber Bragg grating sensor (3, 3', 3'', 3'''), wherein the at least one optical waveguide (2) is surrounded at least partially, in particular in the region of the at least one Fiber Bragg grating sensor (3, 3', 3'', 3'''), by a sheath element (4), wherein the sheath element (4) is a capillary-like element (5), and wherein an elastic body (8) is provided in the capillary-like element (5), wherein said body at least partially fills an intermediate space between the outer circumference of the at least one optical waveguide (6) and the inner circumference (7) of the capillary-like element (5).
Abstract:
An optical fiber system that includes an in-fiber optic component powered by in-fiber light includes an optical fiber having a core, wherein the optical fiber propagates a sensing/signal light and a power light, with the sensing/signal light being propagated in the core. An optical transducing element, such as a layer of light absorbing material, is located in proximity to the in-fiber optic component. An optical tap region is provided in the optical fiber in proximity to the optical transducing element, and enables the power light to leak from the optical fiber and be absorbed by the optical transducing element. The optical transducing element converts the absorbed power light into a second energy form, such as heat, which is used to tune the in-fiber optic component.
Abstract:
The invention relates to a thermally tunable filter comprising an optical fiber (1) containing a Bragg grating (10) on a portion of the fiber (1), a resistive film (6) being in thermal contact with the grating (10), wherein the resistive film (6) is deposited on the external surface of a capillary (7) surrounding the portion of fiber containing the grating (10).
Abstract:
A wavelength selective optical device for locking to a selected wavelength in an ITU grid includes a first waveguide, a second waveguide, a heating element and a control unit. The first waveguide includes a tunable filter formed in the first waveguide and the second waveguide includes a reference filter formed in the second waveguide. The heating element is in thermal contact with the tunable filter and the reference filter and the control unit is coupled to the heating element and the reference filter. The control unit varies a temperature of the heating element responsive to an indication signal provided by the reference filter to adjust the selected channel of the tunable filter.
Abstract:
The present invention is directed to a novel method for preparing chirped Bragg gratings and optical communications devices fabricated therewith.
Abstract:
A method and a device for tuning a Bragg grating in an optical fiber is disclosed. Tuning of the grating is obtained by applying current to at least one longitudinal, internal electrode arranged along the core of the fiber. When current is passed through the electrode, thermal expansion occurs that produces a stress on the fiber core. At the same time, the temperature of the core is increased. This leads to an electrically controlled tuning of the Bragg grating.
Abstract:
The transmission response of an optical filter (BSF) is changed by modifying the temperature thereof. The filter can be adjusted by mechanical pressure or traction. Said filter can be used to create add-drop-continue modules (ZT1,BSF, ZI2) that are suitable for add-drop operations and drop-continue operations. Said optical filters can also be used to create cross-connect modules.